Dear Nereid and Phobos (seat belt on) can we talk about redshifts? [Archive]

meteor

Jun20-04, 01:00 AM

This is the last paper of Arp in Arxiv. It can be interesting for the discussion
http://arxiv.org/abs/astro-ph/0401103
New optical spectra and general discussion on the nature of ULX's
Authors: H. Arp, C. M. Gutierrez, M. Lopez-Corredoira
Comments: submitted to A&A, 8 pages, 5 ps/eps figures

"We present spectroscopic observations of three Ultra Luminous X-ray sources (ULX's). Two of them are very close to the active galaxy NGC 720 and the other is near NGC 1073. The two around NGC 720 turn out to be quasars at z=0.964 and z= 2.216, the one near NGC 1073 seems to be associated to an HII region at the redshift of NGC 1073. We concentrate our analysis on the two quasars and analyze them in conjunction with a set of 20 additional X-ray sources close to nearby galaxies which also fit the criteria of ULX's and which also have been identified as quasars of medium to high redshift. This sample shows an unusually large fraction of rare BL Lac type objects. The high redshifts of these ULX's and their close proximity to their low redshift, supposedly parent galaxies is a surprising result in the light of standard models. We describe the main properties of each of these objects and their parent galaxy, and briefly discuss possible interpretations."

I don't think that Arp is a crackpot, he did a good catalogue of extragalactic objects. But his ideas about intrinsic redshifts seems plain wrong to me.

PS: I've read the article, and at the end of it there's this phrase:
"Another suggested explanation for these association of galaxies and quasars with different redshifts is mesolensing by King objects"

What's mesolensing? What are King objects? I've never heard of that

shrumeo

Jun20-04, 09:55 AM

are these folks trying to discount Harp's interpretations? they don't say outright, only something about "previously proposed ideas"
http://arxiv.org/abs/astro-ph/0310296

can they use their models to predict the redshift differences between the apparenty associated quasar images?

reading the paper, it seems badly translated and parts of it i can't make sense of
grammatically, and yup, the math is over my head, it being optics and gravity and such.

yes, and what is a KING OBJECT, can't find anything about it

edit:
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=ATROES000041000004000436000001&idtype=cvips&gifs=yes

i guess they are supposed high mass objects in the halos of galaxies??
or are they lots of mass spread out over large areas in the halo?

turbo

Jun20-04, 10:11 AM

big-egg

Jun20-04, 04:39 PM

Can somebody tell what are the indications that
the two quasars are at nearly equal distance from us?

Are there firm indications?

turbo

Jun20-04, 05:02 PM

Seyfert galaxy NGC 7603 z=0.029 is connected to its apparently ejected companion z=0.057 by a luminous bridge in which are embedded two compact emission line objects of z=0.243 and 0.391. Scroll down to the images for a look, then read the paper.

http://arxiv.org/abs/astro-ph/0203466

Conservative astronomers claim that these compact high redshift objects are at the distances implied by the Hubble redshift model and the filament is coincidentally projected over them. They also claim that the companion 7603B is at the cosmological distance implied by its redshift which raises the question: Why is there a luminous bridge connecting the two objects if they are too far apart to interact?

A similar question may be asked of M51 and its companion NGC 5195. The conventional answer is that NGC 5195 interacted with M51 a long time ago and is now much farther away, as implied by its redshift. This explanation falls apart pretty readily when viewing deep exposures of the pair, as there is significant tidal action evident, and large masses of material have been displaced from the arms of M51, apparently by the ejection of NGC 5195. Notice the bright blue regions on the inner arm and how they extend out along the path of ejection toward NGC 5195. The path of ejection is apparently in the plane of M51 and not oriented away from us.

http://housefly.astro.princeton.edu/~rhl/PrettyPictures/M51-4x4.jpg

There are many, many more examples of small high-redshift companions interacting with lower-redshift parent galaxies. The conventionalists can explain away individual examples by positing that the the smaller companions are now farther away than the parent galaxies because they have been moving away from us since the (long-ago) interactions. There is a fatal flaw in this thinking: it places us (the observer) in the most special place in the whole universe because the paths taken by these companions all point away from us as implied by their excess redshifts relative to the host galaxies. This simply cannot be true.

It should be evident from these two cases alone that equating redshift with cosmological distance is problematic at best. There are many more examples of interacting high-redshift objects with larger lower-redshift galaxies, though, and I will keep trotting them out, if necessary. If anybody would like to show us a small physically-interacting companion with a LOWER redshift than its host galaxy, please post a link.

What are the benefits of exploring alternative causes of redshifts? The most obvious benefits would be the "normalization" of quasars. If quasars are at the extreme distances implied by their redshifts, they must each possess the luminosity of thousands of galaxies. Furthermore, since many of them exhibit very short-term brightness variations, they cannot be very large - perhaps smaller in extent than our solar system. Since quasars are presumed to be very early, old objects, they must be tremendously organized and concentrated clumps of matter formed very shortly after the Big Bang. What kind of object can be smaller than our solar system and exhibit the energy output of a thousand galaxies, each containing billions of stars? And how could they have organized themselves so readily in such a short period of time? These are very real problems. Big Bang cosmologists have painted themselves into a corner with these outlandish quasar properties, and the corner gets tighter with every "farthest quasar yet" announcement.

To preserve the Big Bang, many are willing to embrace the existence of such implausible monsters. I find the existence of inherent redshifts far easier to stomach. The real question at this point is: what can cause inherent redshift in quasars and other objects? I lean toward a purely gravitational causation because of its simplicity, but the astronomical community needs to address the issue honestly and with some dedication before we can make progress in this regard.

shrumeo

Jun20-04, 11:08 PM

shrumeo

Jun20-04, 11:18 PM

i've seen this paper before http://arxiv.org/PS_cache/astro-ph/pdf/0203/0203466.pdf

when one really looks skeptically at the image, you can explain it away as coincidence that the larger object has a little tail, and the 2nd larger object just happens to be behind it, and the two smaller objects are far behind the tail

I would need to see more examples like this to call it anything other than a coincidence.

turbo

Jun21-04, 06:33 AM

hey, somebody school me on some astronomy!

in this pic http://housefly.astro.princeton.edu/~rhl/PrettyPictures/M51-4x4.jpg

these are two galaxies right?
they must be relatively close to each other to be in the same frame and similar in size? am i wrong? is that not how it works? if they were the same distance apart as say the milky way and andromeda, could someone in another galaxy snap that shot of us from the right angle? Would the milky way and andromeda have similar or different redshifts from that perspective?
Just seeing if anyone has answers to these questions.

Yes, if someone were in the right place, they could photograph our galaxy overlapped by an arm of Andromeda. It would be obvious by the lack of distortion or disturbance of Andromeda's spiral arm, however, that the galaxies are a line-of-sight pair and not interacting.

If you take the name of the jpg out of the URL and paste the remaining URL into your browser, you will find yourself of the Princeton Pretty Pictures page. There you will fine a MUCH-higher resolution version of the same image. Download that and look at it closely. Notice how distorted and pointed the spiral arm of M51 is close to its companion and notice all the filamentous structure around the companion. These are compelling signs of current interaction.

Nereid

Jun21-04, 09:15 AM

Just quickly again, and to be sure that we all have the same field of discussion.

Question to turbo-1: the only data we need consider are apparent interactions between high and low redshift objects, which are either galaxies or quasars, right? If not, what else is in the mix, wrt the cosmological redshift-distance relationship?

Assuming it's just apparent interactions between high and low redshift objects, here are a few preliminary remarks:
- we will have to use statistics to examine the incidence of apparent interactions between high and low redshift objects. Why? Such apparent interactions are certainly rare among Local Group galaxies, and among Virgo cluster ones (the distances to such can be established pretty reliably, and redshifts of these - and almost all but the faintest galaxies and quasars - accurately determined). Being rare, the Arp hypothesis can be properly tested only statistically against the null hypothesis (presumably, that they are coincidences)
- the determination of the distance of an object, independently of its redshift, is important. We should therefore take a good look at what methods are used to make distance estimates, their domains of applicability, the accuracy and consistency of such estimates, etc (this is a fascinating topic of its own)
- galaxies interact gravitationally (duh!), and plenty of them collide. This means that there will be ‘local’ motion of galaxies – the Milky Way toward M31 (Andromeda galaxy), LMC and SMC in orbit around the Milky Way, and so on. Within a cluster, these local motions can be analysed to produce estimates of the total mass within the cluster (assumptions apply); the redshifts which arise from local motion are not part of the expansion of the universe
- quasars and AGNs: we should look at the current models, and discuss the evidence that quasars ‘live’ in galaxies (or, that quasars are ‘merely’ the active nuclei of some galaxies)

Re NGC 7603 and López-Corredoira and Gutiérrez’ paper: IIRC, this was discussed earlier here in GA&C in PF; I think I posted links to HST observations of this object (so we could see for ourselves what the high-z emission line objects look like, at greater spatial resolution), and commented that their calculations of probability (that such an alignment in a filament would arise by chance) were flawed, principally because they didn’t take account of the fact that fainter objects are distributed in a non-uniform way across the sky. In a sense, what López-Corredoira and Gutiérrez did is analogous to assuming that high latitude interstellar absorption is uniform (we know – thanks to IRAS – that it’s not; there are intricate ‘interstellar cirrus’ clouds!)

Phobos

Jun21-04, 12:07 PM

Phobos, chroot: is there some way we can cut&paste turbo-1's two excellent posts, and Phobos' reply, into this thread? It's a great shame the other thread was, in fact, at least three different ones

Now that the thread is in the TD forum, I can't mess with it. Chroot?
For now, here's a link to the TD parent of this spinoff thread...
http://www.physicsforums.com/showthread.php?t=29666&page=1&pp=15

Nereid

Jun21-04, 12:30 PM

If anybody would like to show us a small physically-interacting companion with a LOWER redshift than its host galaxy, please post a link.I believe that the SMC (http://www.seds.org/messier/more/local.html) meets your requirements: it has a radial velocity wrt the centre of the Milky Way of -30 km/sec (i.e. a blueshift). The Magellanic Stream (http://antwrp.gsfc.nasa.gov/apod/ap980826.html) provides strong evidence that it's physically interacting with the Milky Way, and it most certainly is small!

But perhaps this isn't what you meant; would you care to re-state?

turbo

Jun21-04, 05:21 PM

Just quickly again, and to be sure that we all have the same field of discussion.

Question to turbo-1: the only data we need consider are apparent interactions between high and low redshift objects, which are either galaxies or quasars, right? If not, what else is in the mix, wrt the cosmological redshift-distance relationship?

Yes, I think it's appropriate and sufficient to look at apparently-interacting bodies of discordant redshifts. By discordant, I mean a difference significant enough to rule out physical interaction if the objects are presumed to be at the cosmological distances suggested by their redshifts. If even one pair of objects has sufficiently-discordant redshifts to rule out the possibility of interaction and they are observably connected and/or interacting, then the policy of placing every object at the distance dictated by its redshift is negated. I know that there is a cadre of prominent astronomers that have been working at this for many years, but there have been a lot of factors muddying the waters, too, including egos and old grievances. I hope that there can be a rational discourse on the subject on PF, and if there are serious problems with arguments on either side, they can be talked over without anybody fearing the loss of their funding or position. I am an amateur observer/astrophotographer and have no real stake in these cosmology issues.

Nereid - your suggestion of using the SMC and the Milky Way is interesting, :rolleyes: since the redshift component is due to the proper motion of the SMC toward us. That's not what I had in mind, though - you knew that, but I don't mind being tweaked for imprecise statements. The core problem - there are objects like M51 and its companion that are evidently interacting, but have disparate redshifts. If similar pairs are observed, the smaller companion should be travelling toward us (as opposed to away from us) as suggested by its redshift, about 50% of the time. My request was for examples of apparently-interacting pairs where the smaller component has a lower redshift than the host galaxy. If the interactions are real, and the smaller components have predominantly higher redshifts than the host, we must conclude on the basis of cosmological redshift that ejection phenomena and collision events always throw the smaller object away from us - an impossibility.

shrumeo

Jun21-04, 05:22 PM

I asked this question on one of the other threads somehow related to this one. But this topic got spread all over.

It's a dummy, layman question about the optics of the whole apparently-connected-disparate-redshift objects discussion.

It seemed there were a few papers cited (above, in this thread?) that claimed to explain the "Arp objects" as a result of gravitational lensing.

If I were an expert in gravitational lensing, would I expect to see distortion within the images of the quasars? I have seen numerous examples of grav. lensing effects and they are all distorted into arcs or streaks. The "Einstein cross" looks like normal intact objects, but how much "refining" do astronomers do to their data when constructing an image like that? Or are the normal visible images not so "retouched." I'm sure these are stupid questions.

I guess what I'm asking is are these papers claiming to be able to predict the nature of images collected by Arp? Or, are they merely offering an alternative explanation for these observations?

turbo

Jun21-04, 09:40 PM

Lensing has been cited, yes, but the more insidious claims have been the claims of statistical bias. It goes like this: Arp thinks quasars might be ejected from Seyferts and other active galaxies so he searches around them for quasars, and when he finds them, the finds are automatically statistically invalid because he had the temerity to look there. The conventional view claims that he found an apparent excess of quasars around AGN's simply because he looked near them, and if he would just search all the rest of the sky (he might be too old to pull this one off... :uhh:) his observations would fall apart. One problem with this is that the conventionalists explain away every example of discordant redshifts with the claim that Arp's methodology is flawed. Not just Arp, by the way, but the handful of observational astronomers who are still questioning the inflexibility of the redshift=distance rule.

Then when Arp observes that the *highest-redshift* quasars in apparent ejection chains are nearest the active galaxy and the quasars with higher angular separation tend to have less excess redshift, this is also explained away as a statistical problem due to his careless selection of quasar candidates. The problem with the argument of the nay-sayers is that if a significant percentage (and not EVERY SINGLE ONE) of the quasar chains *are* oriented with the higher-redshift quasars nearer the host galaxy, a really significant cosmological problem presents itself. The quasars have somehow conspired to arrange themselves so that if plotted by redshift=cosmological distance, they have lined themselves up in inverted cosmological V's pointing directly away from us. It places us, the observers, in the most special place in the universe, which is impossible.

I don't want to wander too far afield, here, though. If we can discuss the evidently interacting pairs of objects in light of their redshifts, it should keep the discussion focussed...well at least maybe it won't turn into a free-for-all. :smile:

quartodeciman

Jun21-04, 10:08 PM

Turb,

I have read that there are photos of galaxies and apparently associated quasars where the red shifts are concordant. What would be the special significance of these? (maybe quasar shot out sideways?)

Should there not be an occasional quasar that is slightly blueshifted? (if the shifts were entirely cosmological then that would never happen)

Nereid

Jun22-04, 07:46 AM

For those interested (e.g. turbo-1 :wink: ), this is the earlier thread with a discussion of NGC 7603 and López-Corredoira and Gutiérrez' paper (http://www.physicsforums.com/showthread.php?t=8933)

shrumeo

Jun22-04, 12:18 PM

turbo-1, speaking of statistics, how many of these objects have been found so far?

quartodeciman, I don't think they have found enough objects like this to find the one quasar that is being ejected toward us. Also, if the redshift is not attributable to the motion toward or away from us (as Arp claims) then we would also never see a blue shifted quasar "comin' at us".

Also, turbo-1, you say that the redshift seems to be a function of the distance to the galaxy? Can this be explained in terms of gravitational lensing? Again, where is the distortion? (And, of course, lenses have distortions to answer an earlier post, and I'd hope that astronomers correct for them, otherwise this is all a waste of time. After that, where are the distortions normally caused by gravitational lensing?)

Nereid

Jun22-04, 04:55 PM

This page (http://www.mssl.ucl.ac.uk/www_astro/agn/agn_unified.html) has a brief overview of the unified model of active galactic nuclei (AGN), and includes a (very) brief summary of some of the key terms we'll likely encounter - Seyferts (Types 1 and 2), BL Lac objects, AGN, BLR, NLR, accretion disk, jet, ... (be sure to click on the links!).

There are lots of other observations which are now falling into place, wrt this unified model; e.g. 'dark quasars' (X-ray objects that have no optical - or radio - counterpart; X-ray spectrum resembles highly obscured quasar).

Lastly, a nice picture of a molecular torus (http://antwrp.gsfc.nasa.gov/apod/ap991107.html) of an AGN.

meteor

Jun22-04, 05:25 PM

Gibson tries to explain the redshifts discrepancies in the Stephan's Quintet with his hydro-gravitational theory...
http://arxiv.org/abs/astro-ph/0304107
Interpretation of the Stephan Quintet Galaxy Cluster using Hydro-Gravitational Theory
Authors: Carl H. Gibson (UCSD), Rudolph E. Schild (Harvard)
Comments: 21 pages, 3 figures, for Astronomical Journal

Stephan's Quintet (SQ) is a compact group of galaxies that has been well studied since its discovery in 1877 but is mysterious using cold dark matter hierarchical clustering cosmology (CDMHCC). Anomalous red shifts z = (0.0027,0.019, 0.022, 0.022, 0.022) among galaxies in SQ either; reduce it to a Trio with two highly improbable intruders from CDMHCC, or support the Arp (1973) hypothesis that its red shifts may be intrinsic. An alternative is provided by the Gibson 1996-2000 hydro-gravitational-theory (HGT) where superclusters, clusters and galaxies all originate by universe expansion and gravitational fragmentation in the super-viscous plasma epoch (after which the gas condenses as 10^{24} kg fog-particles in metastable 10^{36} kg dark-matter-clumps). By this fluid mechanical cosmology, the SQ galaxies gently separated recently and remain precisely along a line of sight because of perspective and the small transverse velocities permitted by their sticky, viscous-gravitational, beginnings. Star and gas bridges and young-globular-star-cluster (YGC) trails observed by the HST are triggered as SQ galaxies separate through each other's frozen baryonic-dark-matter halos of dark proto-globular-cluster (PGC) clumps of planetary-mass primordial-fog-particles (PFPs). Discordant red shifts (from CDMHCC) between angularly clustered quasars and bright galaxies are similarly explained by HGT.

Nereid

Jun22-04, 05:37 PM

In the other thread, I mentioned that whatever Arp et al had found two decades or so ago, they should be able to find 10x, 100x, or more of in the publicly available datasets. I'd love to have enough time to go through each of these, and compare them with what was available to Arp et al all those years ago (but I don't).

Suffice it to say that these data sets are incomparably richer than anything available when Arp first started his professional career. Too, the tools to analyse such vast quantities of data have advanced considerably; for example, the average 'home user' PC of today, priced under US$1,000, is something that professional astronomers would have killed for not too long ago.

So, the 2dF Galaxy Redshift Survey (http://www.mso.anu.edu.au/2dFGRS/), high quality redshifts of ~250,000 galaxies, by the Aussies. 2QZ (http://www.2dfquasar.org/results.html#example), an ancilliary survey, of ~10,000 quasars (QSOs) - results include the discovery of quasar evolution - pure luminosity evolution (and overcomes one of Burbidge's early criticisms of the identification of QSOs as cosmologically distant, namely, that the redshift-apparent brightness relationship shows no obvious 'distance' component).

SDSS (http://www.sdss.org/background/index.html) (Sloan Digital Sky Survey), whose description is just breath-taking: "[SDSS] will systematically map one-quarter of the entire sky, producing a detailed image of it and determining the positions and absolute brightnesses of more than 100 million celestial objects. It will also measure the distance to a million of the nearest galaxies, giving us a three-dimensional picture of the universe through a volume one hundred times larger than that explored to date. The Sky Survey will also record the distances to 100,000 quasars, ...". The object selection method differs from that of 2dF - and the sky covered overlaps! - so there are lots of opportunities to do nice statistical analyses of completeness etc.

The Hubble Ultra Deep Field (http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/07/), and earlier HDF and HDF-S ... the Hubble Space Telescope spent hundreds of hours collecting photons from small patches of sky. What's not so widely known - outside the astronomical community - is that the same patches of sky were also observed from the X-ray to radio regions of the spectrum, with a huge range of telescopes and instruments. So the EM output of objects in each field is known across a wide range of wavelengths. Related is GOODS (http://www.stsci.edu/science/goods/) - Great Observatories Origins Deep Survey, in which Spitzer will stare at HDF-N and Chandra Deep South (and Gemini and ESO telescopes will also make detailed studies).

Just one more for now: the Subaru/XMM-Newton Deep Survey (http://www.subaru.naoj.org/Pressrelease/2004/06/01/index.html), similar in some ways to GOODS.

Nereid

Jun22-04, 06:13 PM

OK, last one for today ... how do we determine the distance of an object, independently of its redshift? Or, how can the value of the Hubble constant be nailed down?? (remember, the Hubble constant, or Ho, is the local rate of expansion of the universe. Crudely, it's the slope of the redshift-distance line in a plot of datapoints from galaxies; it's units are peculiar - km/sec per Megaparsec!).

This was perhaps the primary goal of the Hubble Space Telescope. The devotion of so much time to what was then the most expensive astronomical instrument is testament to the importance of this result to modern astronomy (and cosmology); the extra-galactic distance scale has been one of the most difficult results to attain, and uncertainties in the determination certainly played a part in the early credibility of Arp et al's papers.

First, a link to the Hubble Key Project papers (http://www.ipac.caltech.edu/H0kp/papers.html). Click on ArXiv preprint to get an electronic copy of a paper.

Next, the final paper, "Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant (http://arxiv.org/abs/astro-ph/0012376)", by Freedman et al.

There are references in this paper - which I encourage PF members and guests to read, it's not that technical, and is one of the milestone papers of modern astronomy - to the following methods of determining extra-galactic distances:
- Cepheids
- Type Ia supernovae
- Tully-Fisher relation
- surface-brightness fluctations
- Type II supernovae
- fundamental plane
- gravitations lensing
- Sunyaev-Zel'dovich.

Perhaps some other PF members would like to post a quick summary of what these methods are?

So, where does all this leave us wrt Arp et al's claims? (At last, something about the main point of this thread!)

Well, for a start, we can be pretty confident that every object whose distance was determined by any of the eight methods above is as far away (in time and space) as that distance estimate (these objects also do not have discordance redshifts). Ergo, they cannot be among Arp et al's list .... or can they?

Then, we should also have a good handle on the "Hubble flow", local deviations from the distance-redshift relationship. Wha??? Best example, the Great Attractor (http://www.solstation.com/x-objects/greatatt.htm).

turbo

Jun22-04, 07:15 PM

OK, let's look at some very basic evidence for interaction here. Please open this paper in a new window and scroll down to the two false color images:

http://arxiv.org/abs/astro-ph/0203466

- The measured redshift of 7603 is 0.029, about the same as that of the filament at 0.030.

- The filament ends in the companion labelled Object 1 at redshift 0.057.

- Since Object 1 is about twice as distant as 7603 (from redshift) it cannot be interacting with 7603 unless the delta redshift is non-cosmological.

- The filament is relatively consistent in brightness and extent the entire distance between 7603 and Object 1. If 7603 and Object 1 are at their cosmological redshifts the filament could not connect them, and if the two objects were even mildly separated, the filament would suffer extinction along its extent toward the more distant object.

Now for the high redshift objects. Let's agree that there is a 100% possibility of finding a very bright high-redshift object in an area the size of the close up (1 square arc-minute = 3600 square arc-seconds). Assuming the luminous filament to be 5 arc-seconds across and 60 arc-seconds long, the filament occupies 1/12 the area of the closeup. There is therefore one chance in twelve that the object can appear projected on any part of the filament. Add a second such object and there is one chance in 144 that both can be touching the filament. What are the chances that both of them will be located in the center of the filament, width-wise? How about 1/60 x 1/60 or 1 chance in 3600? And that's if we believe that there is a 100% probability of finding two bright objects of redshift >0.24 in such a small area.

I know that in an infinite universe, there is a nearly 100% probablility of finding any combination of such objects, but we are not in an infinite "observable" universe. Our observable universe is bounded by cosmological horizons and by the ability of our sensors to detect the things we study.

turbo

Jun22-04, 07:41 PM

Nereid

Jun22-04, 08:17 PM

AFAIK, all the 2dF and SDSS data (to date) is publicly available, as is the HUDF, HDFs, GOODS data, Subaru/XMM-Newton ... in fact, isn't it a Hubble Space Telescope Institute policy that ALL data must be made available to the public (after some time, so the principal researchers can get papers out)? And we're talking here of FITS files, often several GB in size.

Of course, the AAT and SDSS 'scopes aren't as big as Palomar. However, both went pretty deep, so on balance 5-colour CCDs on an optimised 2.5m telescope (plus spectra) isn't obviously poorer than photographic plates on a 5m one.

Did you take a look at the Subaru/XMM-Newton survey? 1.3o (~1,000 times the area as the HDFs), 200 hours observation time, with an 8m class telescope on Mauna Kea, using modern CCDs (BRi'z' observations, limiting B magnitude 28.2; PSF? don't know for sure, I guess it's ~<0.4"), and with SCUBA, BLAST, Spitzer and GALEX observations planned or under way (as well as detailed spectra, with Melipal).

If you've not done so, check out the ASTROVIRTEL website (http://www.stecf.org/astrovirtel/); when that comes on stream, the only thing missing from your dream scenario will be the digitised versions of older plates!

In my list earlier, I left out 2MASS (http://www.ipac.caltech.edu/2mass/), whose data is all fully in the public domain.

turbo

Jun22-04, 09:14 PM

turbo

Jun23-04, 06:21 AM

Nereid

Jun23-04, 09:27 AM

Now that the thread is in the TD forum, I can't mess with it. Chroot?
For now, here's a link to the TD parent of this spinoff thread...
http://www.physicsforums.com/showthread.php?t=29666&page=1&pp=15OK, so here are the previous posts, in chronological order:
An immediate problem I see with the suggested "qualitative" approach (if I understand it correctly) is that it builds the explanatory model first and then finds the data that supports it (ignoring the data against it). In short, a scientist practicing this method would not look for data that can falsify the theory, which is an important part of the scientific method. As I understand it, Burbidge, Arp, et al, are objecting to just this kind of behavior in regard to the Hubble redshift/distance concept. Not only the fault of not looking for insupportive data, but even worse, the ignoring of existing evidence to the contrary. From a basic web page on the scientific method (http://teacher.nsrl.rochester.edu/p.../AppendixE.html):

I. The scientific method has four steps

1. Observation and description of a phenomenon or group of phenomena.

2. Formulation of an hypothesis to explain the phenomena. In physics, the hypothesis often takes the form of a causal mechanism or a mathematical relation.

3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations.

4. Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments.

If observation (for example the observation of apparently causually connected objects with widely disparate redshifts in the case of Burbidge and Arp) disagrees fundamentally with accepted laws, the Scientific Method demands that the observations be examined, disproved, or proved, THEN back to step 2, when the hypotheses are re-examined, if necessary. Unfortunately, the astronomical community has not comported itself well in this regard, and refuses to examine the apparently disparate redshifts critically. There are a number of very compelling examples of apparently physically-associated items with discordant redshifts, but there is precious little attention given to these quandries. It may be that there are other mechanisms beside cosmological expansion that can cause redshift, and the astronomical establishment does itself a disservice to dismiss examples of discordant redshifts so high-handledly without exploring the alternatives.

It may be that the Big Bang is safe and sound, once apparently non-cosmological redshifts are examined and explained. Alternatively, the Big Bang might be threatened if the Hubble constant is re-examined critically. Either way, if the folks that feel that the Hubble constant is flawed should get a fair hearing.

In a June, 1988 letter to me, Halton Arp wrote "While attending the 'Cosmology in Retrospect' symposium in Bologna a few weeks ago I had occasion to reread some of Hubble's old papers. It surprised even me. Hubble always said - 'if the redshift means velocity.' Even in a paper published after his death in 1953 he said that cxz=velocity is not formally correct."

Halton "Chip" Arp is not a crackpot, or even a fringe observational astronomer. He is one of the 20th century's premier observational astronomers, and he has worked closely with some giants of the field. His survey of "interesting" (in the Chinese sense) galaxies is pivotal. When an astonomer of his magnitude makes some very basic repeatable observations and suggests that we need to re-examine some widely-accepted beliefs, we should pay some attention.quantum physics [and Godel, for that matter] predict a certain amount of 'unpredictability' in observations. the best fit theory is as good as it gets. scientists are not dogmatic fools... some of them even have children to support. grant money is not free. they are very careful about what they publish because a single mistake could put an end to their credibility and careers.. or force them to write blame-game occult books about their failed theories to make a living.

Nereid

Jun23-04, 09:34 AM

continued ...Quantum physics deals with the properties and behavior (or lack thereof...) of fundamental particles. It cannot be used to explain variability in macro-world measurements. Variations in measurements of redshift (observations) are not a factor in any case.

There is no dispute that the high-redshift objects cited by Burbidge and Arp are redshifted. The dispute arises out of the insistence of conventional astronomers that redshift is an absolute measure of recessional velocity and thus of distance. Strict interpretation of redshift=distance places quasars very far away, and requires them to be far more luminous than can be accounted for. To complicate this, jets associated with some quasars exhibit apparent superliminal movement which can only be rationalized by asserting some very coincidental alignments. Also, some quasars exhibit brightness changes over short periods of time, suggesting that they are very compact objects. These problems disappear IF quasars are relatively nearby objects and not the most distant observable bodies.

There may be a reasonable explanation for the excess redshift. For instance, quasars might be tremendously massive and compact, and the light from them is redshifted due to climbing out of a steep gravity well. There may be another explanation, but this particular one is so simple and fundamental that it is probably correct - flying in the face of Einstein, who said "elegance is for tailors". :-)Unfortunately, the astronomical community has not comported itself well in this regard, and refuses to examine the apparently disparate redshifts critically. There are a number of very compelling examples of apparently physically-associated items with discordant redshifts, but there is precious little attention given to these quandries.
Do you have some examples we can review?

It may be that there are other mechanisms beside cosmological expansion that can cause redshift, and the astronomical establishment does itself a disservice to dismiss examples of discordant redshifts so high-handledly without exploring the alternatives.
Astronomers recognize cosmological, gravitational, and velocity (doppler) sources of redshift.
In a June, 1988 letter to me, Halton Arp wrote "While attending the 'Cosmology in Retrospect' symposium in Bologna a few weeks ago I had occasion to reread some of Hubble's old papers. It surprised even me. Hubble always said - 'if the redshift means velocity.' Even in a paper published after his death in 1953 he said that cxz=velocity is not formally correct."I have not reviewed Hubble's original papers but even so, a lot of work has been done since that time which is not based on an assumption from his work.

Halton "Chip" Arp is not a crackpot, or even a fringe observational astronomer. He is one of the 20th century's premier observational astronomers, and he has worked closely with some giants of the field.I think its fair to say that he's outside of the mainstream scientific community. (Not that it automatically discounts his work of course, but peer review is important.)
an astonomer of his magnitude

good pun :smile:

Nereid

Jun23-04, 09:37 AM

continued (2) ...Do you have some examples we can review?
he is talking about the Arp objects: http://members.aol.com/arpgalaxy/

there are 388 catalogued http://members.aol.com/arpgalaxy/arpord.html

they are all galaxies/quasars that are clearly close enough to touch/interact- but a doppler redshift would indicate that they are very far away from one another-

I think there is probably some weird gravity effects going on here to cause the discrepancy without the need to attack the doppler-from-expansion or the BB- but unfortunatley mainstream cosmologists and even some astronomers ignore this data because it is often used to discredit the Big Bang- so we are all still waiting for a hypothesis from mainstream science- and waiting- and waiting-Dear Phobos:

Rather than quote, re-quote, etc (kind of messy) I’ll address your quotes one by one.

#1 For some examples, let’s pick just two examples, to keep things manageable:

Here is a link to some information about NGC7603 with two high-redshift knots embedded in the arm connecting the galaxy to its apparently-ejected neighbor. Accidental alignments like this should boggle the mind. If anyone would like to calculate the chances of this alignment, please chime in.

http://quasars.org/ngc7603.htm

Here is a Hubble image of NGC4319 and Markarian 205. Click on the photo and then download the high-resolution version. Open it in Photoshop and manipulate the contrast and brightness settings. The bridge between the two will jump out at you. The Hubble Space Telescope took this picture – there is no sleight-of-hand here. The official version of the image is pretty mundane. Even minor enhancement brings out the bridge, though.

http://hubblesite.org/newscenter/ne...leases/2002/23/

#2 Yes, of course astronomers acknowledge that there are various means by which light can be redshifted. The problem is that the astronomical community has determined that the observed high redshifts of quasars are primarily (read “entirely”) cosmological. If there is even ONE convincing example of a physical relationship between a high-redshift object and a low-redshift object, this rule-of-thumb is automatically void and needs to be re-validated.

#3 I have no access to Hubble’s original papers either. Halton Arp has been privileged to work with some of the finest observational astronomers, however; well before their work was entombed by the assumptions of others. His first position after attaining his doctorate was as Edwin Hubble’s assistant, and I expect that he has a deeper appreciation for Hubble’s thought-processes than most contemporary astronomers. The quote is from a fairly long letter Dr. Arp wrote to me in response to another letter I had written to an astronomy magazine in regard to the apparent bridge between Q2203 +292 and a nearby spiral in a recently published photo. He wanted to convey to me that even Edwin Hubble was uncomfortable with the current fad of using redshifts to establish the distance to every observable object. There is an old saying - “to a man with a hammer in his hand, every problem looks like a nail”. It might now be appropriate to ask if the Hubble Constant has been plastered onto quasars and other high-redshift objects even before the natures of such “quasi-stellar” objects have been adequately explored.

#4 Being outside the mainstream does not invalidate Arp’s work. Copernicus and Galileo were outside the mainstream. Einstein was outside the mainstream. People who make paradigm-altering observations are always outside the mainstream until their observations are accepted. That does not make them wrong, nor should it lay them open to ridicule. I wonder how Galileo would have survived under “peer review” if he had not already used his telescopes to demonstrate to other inquisitive individuals that he was onto something. He probably would have died very early in the inquiry, like the other heretics.

#5 Not a pun (although I love them). Halton Arp is a real gentleman. 50 years from now, the people who have done their very best to bury him in these past few decades will be discredited and many will be reviled for their efforts to discredit him. He is a decent man, and he comports himself with dignity.

Nereid

Jun23-04, 09:40 AM

Last one (can't resist) ...ditto...hang on, Turbo1
Oy - fasten your seat-belt, turbo1. You don't know what you just got yourself into...I must say that I really have no idea what Russ could have meant! :wink: :eek: :yuck: :uhh: :surprise: :rolleyes: :biggrin: :smile: :shy: :tongue2:

Chronos

Jun23-04, 06:29 PM

Now for the high redshift objects. Let's agree that there is a 100% possibility of finding a very bright high-redshift object in an area the size of the close up (1 square arc-minute = 3600 square arc-seconds). Assuming the luminous filament to be 5 arc-seconds across and 60 arc-seconds long, the filament occupies 1/12 the area of the closeup. There is therefore one chance in twelve that the object can appear projected on any part of the filament. Add a second such object and there is one chance in 144 that both can be touching the filament. What are the chances that both of them will be located in the center of the filament, width-wise? How about 1/60 x 1/60 or 1 chance in 3600? And that's if we believe that there is a 100% probability of finding two bright objects of redshift >0.24 in such a small area.

I know that in an infinite universe, there is a nearly 100% probablility of finding any combination of such objects, but we are not in an infinite "observable" universe. Our observable universe is bounded by cosmological horizons and by the ability of our sensors to detect the things we study.

I think it is reasonable to predict, given the number of galaxies we can observe, that it is highly improbable such coincidences would not be found. The article Nereid referred to regarding HST findings related to the Hubble constant is much more convincing than Arp's portrait gallery of freaks of nature.

I also think Arp, while well intended, is statistically challenged and has a history of using dubious math to arrive at equally dubious conclusions: which is why he does not have much mainstream support. A good example is the Newman-Terzian paper http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995ApJ...441..505N&db_key=AST&high=3325b47acc06425

The book of nature lies continuously open before our eyes (I speak of the Universe) but it can't be understood without first learning to understand the language and characters in which it is written. It is written in mathematical language, and its characters are geometrical figures. - Galileo Galilei

Nereid

Jun24-04, 09:13 AM

This (http://www.gemini.edu/project/announcements/press/2004-13.html) recent study of a very massive, mid-distance cluster (z~=0.5) combines observations from Chandra, Keck, Subaru, and Gemini-N. It is part of a set of programs aimed at discovering the evolution of LSS (large scale structure), in particular how galaxy clusters came to have the size and structure that we see today. The role of 'filaments' is important in this.

Interestingly, the astronomers found indications that "significant dynamical activity at scales greater than 5 Mpc from the cluster, well beyond the virial radius. The observations imply an in-fall of matter along this preferred axis direction. The funneling will persist for roughly the next 4 Gyr, assuming an in-fall speed of ~1000 km/s."

Nereid

Jun24-04, 09:19 AM

Hubble, Galaxies Across Time and Space (http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/16/) is an IMAX film based on the GOODS (http://www.stsci.edu/science/goods/) survey.

As there are ~30,000 galaxy images in GOODS, of which ~11,000 have measured redshifts, this might be a good test of the Arp hypothesis - how many 'discordant redshifts' appear in the GOODS data? AFAIK, all results are in the public domain, so anyone can check the selection methods used, for determining what constitutes a 'galaxy', and for interpreting spectra in terms of redshift.

In some ways it's a pity this is already 'finished'; otherwise we could ask Arp (or supporters) what they would expect to find in such a survey, and compare their predictions with the observations.

Nereid

Jun24-04, 02:08 PM

How big are the public GOODS* data files? Seat belts on please (just the HST BViz observations) ... " The files for each section, both the science and the weight map images, are ~268.4 MB in size each (8192 x 8192 pixels, each with a 32 depth), and there are images in each of the four GOODS passbands. Thus, the CDF-S data set requires 2x268.4x18x4 = 38.655 GB, the HDF-N requires 2x268.4x17x4 = 36.507 GB. The full data set requires 38.655 + 36.507 = 75.162 GB."

*"GOODS will survey approximately 300 square arcmin divided into two fields: the Hubble Deep Field North and the Chandra Deep Field South. These are among the most data-rich portions of the sky, and are the sites of the deepest observations from Hubble, Chandra, ESA's XMM-Newton, and from many ground-based facilities. Dividing our survey area provides insurance against cosmic variance due to galaxy clustering, and guarantees that astronomers in both hemispheres can carry out related observations." ... and Spitzer too.

big-egg

Jun24-04, 02:52 PM

Are the disparate red shifts associated only with quasars and galaxies?

Are there coupling galaxies with disparate red shifts?

Are there supernovas in the proximity of the quasars?

What about the quantum red shifts? They will also create a hard problem to the BBT.

Are there statistical steadies on disparate red shifts?

Thank you for your time to consider these thought provoking questions.

turbo

Jun24-04, 05:05 PM

I also think Arp, while well intended, is statistically challenged and has a history of using dubious math to arrive at equally dubious conclusions: which is why he does not have much mainstream support. A good example is the Newman-Terzian paper http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995ApJ...441..505N&db_key=AST&high=3325b47acc06425

I am very surprised that you cited that statistically flawed paper, but I am very happy that you did so. The authors misstated Arp's premise and then applied statistics in a very creative way :eek: to downplay the improbability of something truly implausible.

Let's say you have a large galaxy and eleven associated smaller galaxies, clusters, whatever. If the smaller objects are physically associated with (and effected by) the more massive object, we would reasonably expect about half the smaller objects moving around that massive galaxy would be moving toward us relative to the host, and would therefore be blueshifted in relation to the host. If the host has one object it around it, there is one chance in two (1/2) that the object would be redshifted with respect to the host. If there are two objects, there is one chance in four (1/4) that both objects would be redshifted relative to the host. To save time, we will extrapolate: if there are eleven objects around the host, there is only one chance in 4096 that all eleven objects will be found to be redshifted relative to the host.

In the paper cited above, the authors de-coupled the massive host galaxy from any effects on the associated small objects, and then restated the problem as a simple matter of ordination, saying in effect "there is one in twelve chances for the host galaxy to have the smallest redshift so that's a 1/12 chance for the observation that all the smaller objects will be redshifted relative to the large massive galaxy." That has to be one of the most cynical applications of "statistics" I have seen.

The problem that Arp was illustrating is that lower-mass companions of large galaxies are preferentially redshifted with respect to their hosts (like M51 and NGC 5195). It is easy to statistically refute the significance of this trend with one or two objects, but when smaller objects are overwhelmingly found to be redshifted relative to their host galaxies, there can be only two explanations - either we are at most privileged position in the whole universe, where all smaller objects are preferentially running away from us heedless of the gravitational effects of their host galaxies OR these smaller objects have an additional intrinsic redshift that we don't yet understand. I prefer the latter.

meteor

Jun24-04, 07:01 PM

"A catalogue of southern peculiar galaxies and associations" (Arp, 1987)
http://nedwww.ipac.caltech.edu/level5/SPGA_Atlas/frames.html

This catalogue includes galaxies that are apparently connected. Can be an useful source of information

Also, in post 119 of this thread
http://www.physicsforums.com/showthread.php?t=3593&page=3&pp=40
I give my explanation of the fact that two objects with different redshift seems to be connected

Chronos

Jun25-04, 01:18 AM

How can you not give an 8% chance that any one of 12 objects in a group is the least red shifted among the group? The main point of the Newman-Terzian paper was point out the flawed initial assumption Arp used. Intrinsic red shift is a very unsatisfactory explanation. Why would less massive bodies have more intrinsic red shift than the most massive body in a group? The preponderance of evidence supports the conclusion that z=distance. Arp's 388 potential 'exceptions' should not be given more credence than the overwhelming number of confirmations in support of expansion and the BB model. Exceptions, however, are interesting, and point the way to more refined explanations. That only means the current model is incomplete, not fundamentally wrong. Give credit where credit is due. We already know the current model has problems. Quantum physics and GR just dont mix without a quantum theory of gravity. I dont like the idea of appealing to higher orders of reality to explain the problem. Adding strings and branes, imo, only creates more difficulties than they resolve... 'mommy, where did strings come from?'. I think it is a mistake to stray from the observable universe into the unobservable to find answers. It flys into the face of science as I know it.

turbo

Jun25-04, 08:30 AM

How can you not give an 8% chance that any one of 12 objects in a group is the least red shifted among the group? The main point of the Newman-Terzian paper was point out the flawed initial assumption Arp used.

The problem with the "statistical treatment" of the example is that the authors of the paper stripped out causality with regard to the gravitational influence of the largest body - it was ignored completely. If you were to make some observations relating to the movements of bodies in our solar system, surely you would not use a method that disregards the gravitational influence of the sun! This is exactly what the authors of that paper did.

To restate:

There are eleven relatively small objects in the domain of one very large massive object.

The motions of the small objects orbiting the massive host object have a 50:50 chance of being toward us or away from us relative to the host.

If the host has one object it around it, there is one chance in two (1/2) that the object would be redshifted with respect to the host. If there are two objects, there is one chance in four (1/4) that both objects would be redshifted relative to the host. To save time, we will extrapolate: if there are eleven objects around the host, there is only one chance in 4096 that all eleven objects will be found to be redshifted relative to the host.

This is very basic statement of probability. If there is 1/x probabilty of an object being in a particular state, the probability of a set of objects with y members all being in that state at one time is 1/(x to the y power). It's hard for me to understand how the Newman-Terzian paper was published with such a very glaring basic statistical error.

Intrinsic red shift is a very unsatisfactory explanation.

The explanation may be unsatisfactory, but that does not invalidate the observations. The scientific method requires that if we cannot disprove the observations, we must come up with a model that explains them, and use the model to make testable predictions that can be used to verify, disprove, or refine the model.

Chronos

Jun25-04, 03:39 PM

Turbo: Objections noted. Not all apparent redshift anomalies have been satisfactoriy explained using the standard model. Progress is, however, being made. So far as Newman-Terzian is concerned, I am not aware of any published studies refuting their position. I would be interested if you know of any references.

Chronos

Jun25-04, 03:54 PM

turbo

Jun25-04, 04:57 PM

Nereid

Jun25-04, 05:56 PM

To restate:

There are eleven relatively small objects in the domain of one very large massive object.

The motions of the small objects orbiting the massive host object have a 50:50 chance of being toward us or away from us relative to the host.

If the host has one object it around it, there is one chance in two (1/2) that the object would be redshifted with respect to the host. If there are two objects, there is one chance in four (1/4) that both objects would be redshifted relative to the host. To save time, we will extrapolate: if there are eleven objects around the host, there is only one chance in 4096 that all eleven objects will be found to be redshifted relative to the host.

This is very basic statement of probability. If there is 1/x probabilty of an object being in a particular state, the probability of a set of objects with y members all being in that state at one time is 1/(x to the y power). It's hard for me to understand how the Newman-Terzian paper was published with such a very glaring basic statistical error.I'll get back to this in more detail when I've read more, but just quickly ... the tidal locking of Io, Europa, and Ganymede means that the probabilities of 'N moving towards' vs 'M moving away' is not random, so the probabilities turbo-1 describes would not apply (actually, *could* not apply). There's also measurement error - how many 'small' objects would show essentially zero redshift (wrt something), within the measurement error?

turbo

Jun25-04, 09:36 PM

Chronos

Jun26-04, 01:10 AM

Thanks for posting that paper. Similar to your discomfort with intrinsic redshifts, I have a problem getting comfortable with the concept of quantized redshifts. My gut feeling is that there is a very simple understandable reason for discrepant redshifts, and that once we figure out the mechanics, the cause will be something that causes a smooth continuum of redshift, not a stepwise progression.

we are in agreement. i respect your objections and agree that current models are lacking. we need better predictive models to sort it out. something is still missing. the universe is a maddening puzzle. it taunts and teases us, but, resists yielding its secrets. i do believe, however, current models are more correct than incorrect. the evidence appears, at least to me, to be overwhelming. the piece still missing, imo, is quantum gravity.

are there observations that contradict expansion as the 'big picture' of the universe? of course. information theory [shannon and godel] insist this will always be the case. will someone find a paradigm shift to further advance our understanding of how the universe works? i hope so. i object to being trapped within a place as small as our solar system. that is what current theory condemns us to and i am not comfortable with that either. if we can see it, we should be able to explore it.

Nereid

Jun26-04, 08:46 AM

Mesolensing is in between microlensing (point-like mass) and macrolensing (galactic-like mass) and has been proposed as a means by which to indirectly observe CDM. The means proposed is to observe multipli-imaged quasars and to record any phasing anomalies, and from those infer the mass and/or extent of the CDM doing the lensing.

King objects aren't a class or type of object, if I understand correctly, they are objects that conform to a particular model of mass distribution, and they have been invoked in the form of galactic halos to explain away the statistical preference in some studies for quasars to appear in closer (angular) proximity to galaxies than can be accounted for by chance.Am working my way slowly through the posts in this thread, and have got up to here.

Several questions, and possible lines of investigation, occur to me:
- examine the Arp hypothesis (-ses?), that AGN galaxies (inc Seyferts) eject quasars (yes, that's an oversimplification); that the preponderance of galaxy/quasar discordant redshifts also involve ULX. I'm not sure yet what to do about his galaxy/galaxy discordant redshift observations.
- take a closer look at gravitational lensing - micro, meso, and 'traditional'
- GOODS, 2dF, and SDSS as tests of Arp's ideas. e.g. if there are ~300 'Arp' objects among the ~23k de Vaucouleur catalogue (RC3 (http://archive.eso.org/starcat/astrocat/rc3.html)), then there should be ~300 among the 30k GOODS galaxies, and ~3k among the ~250k 2dF ones, and ~10k among the ~1m Subaru/XMM-Newton ones (many assumptions behind these statements!); are there?
- both 2dF and SDSS should permit a far more rigorous testing of any quasar/(active) galaxy association than finding interesting objects by eye and taking a deeper look; medium-deep surveys should also provide good tests
- among objects whose distance has been established by means independent of redshift, there will likely be some from Arp's catalogue, and surely some Seyferts (etc). What about associated discordant redshift objects? E.g. an SN in both objects of such a pair? We can look for ourselves, because there's a pretty complete list of all SN available on the internet.

Finally, some clarifications on King objects, meso-lensing, CDM cosmology, etc.

One of the challenges for the concordance model ('\Lambda CDM') is that it predicts far more 'small(ish) galaxies' than are actually observed, IIRC between 1 and 2 OOM too many. Now the model doesn't say what sort of things these objects should be, just (approx) what their mass function should be (how many of mass M1, how many of mass M2, etc), and (approx) the distribution of mass within them (hence 'King objects'; OK some oversimplification here too). Most importantly, it doesn't distiguish between baryonic matter and dark matter! Enter theories of galaxy evolution, and where it starts to get messy; enter observations, and where it starts to get interesting! Even within the Local Group - the ~20 (30?) galaxies dominated by the Milky Way and M31 - we keep finding more and more things, such as dwarf galaxies like Andromeda 9 (http://www.sdss.org/news/releases/20040531.andromeda9.html), dwarf galaxies being shredded by the MW, and inter-galactic clouds of gas. But the critical thing is the DM, which, because it's dark, can't be 'seen' in X-rays, the optical, radio, etc. However, DM objects can be detected through gravitational lensing; the question is, what sort of gravitational lens signature would a DM object leave on the light (radio, X-rays, etc) from a distant quasar? Or, within an Arp hypothesis, what should the results of observations designed to find 'meso-lensing by King objects' be?

turbo

Jun26-04, 11:08 AM

There is such a ton of research material available...

Nereid, your suggestions re: SN in Arp objects led me to this great SN list

http://web.pd.astro.it/supern/snear.txt

and I started comparing it to the Arp catalog, which is a pain in the butt. Differences in nomenclature make it very likely that I would miss Arp objects in the SN catalog.

http://members.aol.com/arpgalaxy/arplist.html

I decided to cut to the chase and Googled supernova and Arp and found this article about multiple SN in Arp 299:

http://www.space.com/scienceastronomy/aas202_supernova_030527.html

Which led me to explore Arp 299 in more detail. There is wealth of material in NED, of course, and there is a nice Arp 299 page here:

http://www.cv.nrao.edu/~jhibbard/a299/a299.html

It seems that Arp 299 might be a little "too" complex for the SN data to be really useful, as evidenced by this really busy paper:

http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v532n2/50399/50399.text.html

I will try to locate a more "normal" Arp pair with SN data available. Can anyone suggest a more productive approach to locating SN data in apparently-interacting objects with discordant redshifts?

Nereid

Jun26-04, 08:08 PM

The list of SN that you found seems similar to the 'official' one, associated with the IAU circulars (CBAT - Central Bureau of Astronomical Telegrams - is currently administered by the Smithsonian Astrophysical Observatory?); here (http://cfa-www.harvard.edu/iau/lists/RecentSupernovae.html) is their list of SN since the start of 2003 (there's also a link to all SN).

You may find the best way to find a match is to put the list into a database or spreadsheet, sort by RA (or dec), filter by close matches to Arp objects (I assume you have a list of their RAs and decs), and examine each such in detail.

Be aware that even the IAU list has errors in it! They seem to be mostly typos (e.g. transposed digits).

Chronos

Jun27-04, 02:01 AM

turbo

Jun27-04, 09:16 AM

well, i hoped to blow the whole arp thing out of the equation. the preponderance of evidence says arp is wrong. i referenced two papers that explain why i am persuaded to think how i do. if you wish to change my mind, offer me papers that refute them. i have great respect for terzian as a scientist. his credentials are impeccable. he has published many papers and is highly respected in the scientific community. no one, to my knowledge, has ever refuted his papers. you dont achieve the honorary chair of cornell university by being a quack. apologies. if mr terzian cared to speak here, we should listen.

You don't need someone with a Phd to refute the Newman-Terzian paper for you. Trust your own abilities. Read the paper and you will see that the authors (with lots of hand-waving and misdirection) ignored the central point of Arp's argument - that the smaller bodies are under the gravitational influence of the large body and therefore must exhibit some predictable behavior in their motions relative to the host. After butchering the model by ignoring gravity, they then treated the redshift relationships as a matter of simple ordination, saying that the bodies are all essentially equivalent, and that there is a 1 in 12 chance (8%) that the largest galaxy will have the smallest redshift. Those methods are so basically wrong, the paper should never have gotten past the referees.

Just sketch out the model on a piece of paper (large galaxy surrounded by 11 smaller bodies), assign some orbits to the small bodies and then imagine the coincidence (one in 4096) that would have to occur for ALL the smaller bodies to be moving away from us relative to the host. Here's a wrinkle: :devil: When you sketch out the model, assign one of the bodies an orbit that is about perpendicular to our line of sight. Now, try to arrange for that object to have a redshift relative to the host without invoking an intrinsic redshift of some kind. :eek:

Once you have sketched out the model and done some thought-experiments with it, re-read the Newman-Terzian paper. The flaws in their analysis will become immediately apparent. It's not rocket science.

Added 2:40pm...... Let's do a really simplified example, with all objects in about the same plane around a central body - just like our own solar system. To an observer outside our "solar system" each "planet" would have measurable redshift relative to the sun less than 50% of the time. There would be no measurable redshift near transit or occultation and there would be blueshift on the other side of the orbit. If the outside observer noted ALL NINE "planets" being redshifted relative to the sun he would surmise (and rightly so) that he was observing a very special and rare alignment, with less than one chance in 1024 of ocurring at the particular time of his observation. He would not say "well, there are 10 objects in that system, so there is one chance in ten that the central object would have the least amount of redshift." At least he wouldn't say that if he had any sense. The Newman-Terzian paper uses exactly that approach to "refute" Arp. You don't need a Phd to invalidate the Newman-Terzian paper, just grade-school math and some common sense.

Chronos

Jun30-04, 04:03 AM

turbo

Jun30-04, 06:33 AM

Orientation could matter. If the axis of rotation is pointed at the observer, all bodies in the associated group would have indistinguishable redshifts. The lack of relative blue shifts is more puzzling than explanatory

Exactly! When orbit inclination is taken into account, we should expect the smaller objects to have significant redshifts with respect to the host less than half the time. Finding 11 out of 11 small objects around a large galaxy to be redshifted relative to the host is actually much more implausible than Arp calculated. He used a simple 50:50 (redshift-blueshift) calculation, which is generously conservative.

shrumeo

Jun30-04, 07:06 PM

why were they assuming that the smaller bodies are orbiting the larger galaxy?
what was the indication that they were gravitationally associated?
I forgot, sorry.

shrumeo

Jul1-04, 03:56 PM

Sorry for mixing threads but I hope someone could clear this up.

This came from "Seeing Red" thread:

In this page comes the formula for the calculation of gravitational redshift for a photon emitted from a star
http://en.wikipedia.org/wiki/Gravitational_redshift

z= \frac {G}{c^2}* \frac{M}{R}

M is the mass of the star and R its radius

I guess I never thought to try something as simple as pluggin in to this eq. so I tried it for a typical quasar (or at least how it's typically described). So I replied with:

so a quasar is supposed to have a mass comparable to a galaxy
i will say a typical galaxy holds 10b stars,
let's just say our hypothetical quasar has 10b solar masses
IIRC, a typical quasar has a radius comparable to the solar system
I will just say 30 AU

mass of sun = 2.3 x 10^33 g (from the Wikepedia page)
10b x this = 2.3 x 10^43 g
radius of 30 AU ~ 4.5 x 10^14 cm

plugging these into the equation above, I get a gravitational redshift from a typical quasar to be z=3.78 !

Please tell me if my assumptions are wrong.
Thanks :biggrin:

shrumeo

Jul2-04, 02:26 PM

Oh, wait, they are wrong. I was using the approximation for a small star.
When you use the real eq. you realize there is a limit to M/R, otherwise you are a black hole. Sorry for blemishing this thread.
:)

turbo

Jul3-04, 02:29 PM

Nereid

Jul5-04, 06:46 PM

Here is a very compelling example of interacting galaxies that appear (if redshift=distance) to be simply a chance projection. The authors evaluate the pair in light of morphology, redshift, rotational speed, etc, and conclude that the galaxies must be interacting despite their widely disparate redshifts. Go to the page below and get the scanned refereed PDF article.

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1994ApJ...432..135M

There are a number of very good photographs of this pair on the 'net. Here is a page containing some interesting pictures of interacting galaxy pairs, including this one.

http://www.astr.ua.edu/pairs2.htmlDon't you mean UGC 807?

I note that the Arp et al paper which you cite was published in 1994; I also note that NGC 450 and UGC 807 were the subject of several Hubble observations - images and spectra - how do Arp et al's claims stack up in the light of the much higher resolution HST observations?

If anyone's intetested, here (http://archive.stsci.edu/cgi-bin/genlinks_search.cgi?target=NGC450&resolver=SIMBAD) is a place you can start your search for raw data, to perform your own analyses ...

turbo

Jul5-04, 08:36 PM

You're right of course. I slipped a number key (l-r) when typing - I'm an acceptable touch-typist most times, but have trouble with numbers, and didn't catch it in proofreading.

At any rate, UGC 807 (with the higher redshift) appears more likely to be in front of NGC 450 than in back of it, and there are morphological problems between the pair that point to interaction - these are not a chance projection.

http://nedwww.ipac.caltech.edu/level5/index.html

There are some really wonderful atlases here, where lots more of these conundrums can be found.

turbo

Jul6-04, 04:40 PM

I note that the Arp et al paper which you cite was published in 1994; I also note that NGC 450 and UGC 807 were the subject of several Hubble observations - images and spectra - how do Arp et al's claims stack up in the light of the much higher resolution HST observations?

The exposures with HST's wide-field planetary camera are very crisp, but not deep. They don't respond well to my FITS viewer's contrast function, either. I would be very interested in seeing if Arp et al's redshift measurements of NGC 450's HI regions are confirmed, but don't know if this work has been done, or can be extracted from raw data already collected.

On another front:

Here is a link to a paper in which photometric measurements were done to determine the level at which NGC 450's disc diminishes the light of UGC 807. Interestingly they found no measurable extinction - even though there must be a 10x more massive halo of dark matter around NGC 450. I guess it MUST be non-baryonic matter. :devil:

http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1992A%26A...265..396A&db_key=AST&page_ind=0&plate_select=NO&data_type=GIF&type=SCREEN_GIF

If indeed UGC 807 is slightly in front of NGC 450 (as it appears to me in deep exposures),

http://www.sdss.org/news/releases/20010605.edr.img18.html
http://160.114.99.91/astrojan/Ngc/ngc0450.gif

their result (no dimming) is to be expected, although it throws redshift=distance in the trash. It would be intersting to see a similar analyses to see if the light of NGC 450 suffers extinction due to absorption by the disc of UGC 807. :rolleyes:

Nereid

Jul9-04, 08:03 PM

Today's APOD (http://antwrp.gsfc.nasa.gov/apod/ap040709.html) is a very nice piccie of M57 (the Ring Nebula) and IC 1296. If the two had been just a few ' closer together - on the sky - would someone have considered it strong evidence of interaction?

For sure, no one (seriously) today, but in the first couple of decades of last century ...

Of course, Arp et al are careful to try to distinguish mere coincidences (not) like this from possibly real things (yes, I will continue reading the posts in this thread); beyond Arp, how does one go about clearly demonstrating 'mere' coincidence?

Let's also mention Stephan's Quintet (http://antwrp.gsfc.nasa.gov/apod/ap001113.html). IIRC, turbo-1's earlier post in this thread on SQ implies that Arp (or colleagues, or turbo-1) insisting that NGC 7320 (the blue spiral) is actually interating with the other galaxies in the quintet. If this stance is still being taken, I guess we can conclude that one of the redshift-independent methods to determine distance is contra-indicated (according to the discordant redshift brigade), namely surface-brightness fluctuations; in the HST image, NGC 7320 clearly has greater such fluctuations than NGC 7318A, 7318B, and 7319. So we could reasonably ask, which of the generally accepted, non-redshift methods of estimating distances* DO they accept as valid?

*from the Freedman paper on the Hubble constant:
- Cepheids
- Type Ia supernovae
- Tully-Fisher relation
- surface-brightness fluctations
- Type II supernovae
- fundamental plane
- gravitations lensing
- Sunyaev-Zel'dovich.

turbo

Jul10-04, 10:59 AM

Today's APOD (http://antwrp.gsfc.nasa.gov/apod/ap040709.html) is a very nice piccie of M57 (the Ring Nebula) and IC 1296. If the two had been just a few ' closer together - on the sky - would someone have considered it strong evidence of interaction?
Even if we had no clue about the nature of those two objects, there is nothing in their morphology (in this very beautiful image!) that suggests interaction. Anomalous star formation, tidal disruption, etc.

beyond Arp, how does one go about clearly demonstrating 'mere' coincidence?
There's the rub. The universe is a pretty big place :smile: so when a researcher points to an apparently-interacting pair of objects with discordant redshifts, conventional cosmologists can (very logically) say "given the number of objects in the universe, we should expect to see coincidental alignments like this" as they casually dismiss the observation. It is not incumbent on conventional cosmologists to demonstrate coincidence, nor is it politically expedient to spend much effort or time at it. When someone does take the time to critique the work of Arp, Burbidge, et al, their critiques are often accepted as fact, even when their analyses are badly flawed, like the Newman-Terzian paper cited in a post above.
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995ApJ...441..505N&db_key=AST&high=3325b47acc06425

Let's also mention Stephan's Quintet (http://antwrp.gsfc.nasa.gov/apod/ap001113.html). IIRC, turbo-1's earlier post in this thread on SQ implies that Arp (or colleagues, or turbo-1) insisting that NGC 7320 (the blue spiral) is actually interating with the other galaxies in the quintet.

I didn't cite Stephan's Quintet as an example of interaction between discordant-redshift galaxies. I think the high resolution imagery from HST put that one to bed years ago. There are, however, examples of apparently-interacting objects with very discordant redshifts, one of which I mentioned in one of the first posts in this thread.

Seyfert galaxy NGC 7603 z=0.029 is connected to its apparently ejected companion z=0.057 by a luminous bridge in which are embedded two compact emission line objects of z=0.243 and 0.391. Scroll down to the images for a look, then read the paper.

http://arxiv.org/abs/astro-ph/0203466

Conservative astronomers claim that these compact high redshift objects are at the distances implied by the Hubble redshift model and the filament is coincidentally projected over them. They also claim that the companion 7603B is at the cosmological distance implied by its redshift which raises the question: Why is there a luminous bridge connecting the two objects if they are too far apart to interact?
It would be helpful for the reader to load the paper above and scroll down to the false-color images. Look at the morphology of the system and for a moment, pretend that the redshifts of these objects have not yet been measured. There is a luminous filament extending from the Seyfert to the ejected object. Most reasonable people would say that these objects are interacting, similar to the M51 system. Now, measure the redshifts of the objects. Suddenly, this obvious example of interaction/ejection turns out to be a chance projection with NO chance of interaction.

How can this be? It's because conventional cosmologists "know" with 100% certainty that the redshifts of these objects are due to cosmological expansion, that's why! There are no questions left unanswered about redshift. Well, there's the little question about why young supermassive stars in our own galaxy and others are streaming directly away from us in every direction (K-effect), but that's a minor quibble! We already know everything there is to know about redshift.

Sarcasm aside, if young supermassive stars in our own galaxy can exhibit intrinsic excess redshift, is it possible that some extra-galactic bodies might also have intrinsic redshifts? The orthodox astronomical community rejects that possibility out-of-hand, and that's bad science. It might be that Lopez-Corredoira and Gutierrez are wrong about NGC 7603. It might be that Arp et al are wrong about NGC 4319 and Markarian 205 and every other example of apparently-interacting objects with discordant redshifts. If only one of these numerous apparent interactions is real, however, (not ALL of them, only ONE of them) the simplistic redshift=distance rule is in for some serious modification, and we have a LOT of work to do.

Nereid

Jul10-04, 04:39 PM

You may find this interesting: http://arxiv.org/PS_cache/astro-ph/pdf/0208/0208117.pdfThank you Chronos, a most interesting read.

This paper should allow us to put several 'association' and 'quantized z' hypotheses to sleep. Does anyone know if any serious astronomers in either of those camps are still banging those drums?

Now that some SDSS results are in the public domain, perhaps a similar piece of research could be done using those? The good news is that SDSS uses a completely different method to select objects for specta than 2dF did, so if similar analyses of the two datasets yield similar results there'll surely be no place to hide!

I particularly liked the approach taken here: a proponent in one camp suggests a method of analysis, and a neutral third party carried out the work, using publicly available data. What's good? The method and expected outcomes were clearly defined BEFORE the work was done, and the datasets are in the public domain (you don't like the conclusions? there's nothing at all stopping you from performing your own analyses!)

Nereid

Jul10-04, 04:51 PM

Thank you for your time to consider these thought provoking questions.Good questions, big egg. :approve: Some quick, but not necessarily complete, answers:Are the disparate red shifts associated only with quasars and galaxies?

Are there coupling galaxies with disparate red shifts?Arp et al (and turbo-1) would claim there are plenty of galaxy-galaxy ones; almost everyone else would say that any such are chance alignments (billions of galaxies detectable by the likes of the VLTs, Geminis, Kecks, HST, etc; chance alignments will occur by the thousands, maybe millions)Are there supernovas in the proximity of the quasars?turbo-1 is checking that; by simple random probability, there will surely be some. Of course, it also depends on what you mean by 'proximity'! A dedicated observational campaign would surely find lots of SN associated with quasars. SNAP (http://snap.lbl.gov/) is one project that would help answer this; let's all work together to help ensure it gets off the ground!What about the quantum red shifts? They will also create a hard problem to the BBT.When data was sparse, you could crunch the numbers and show tantilizing hints of such quantization; with 2dF (and now SDSS) in hand, all such hints have evaporated.Are there statistical steadies on disparate red shifts?Yes; see the paper which Chronos provided a link to.

Nereid

Jul10-04, 05:11 PM

http://www.naoj.org/Science/SubaruProject/SDS/scijust_qsos.html

There is ongoing work that can help eliminate the quasar-candidate selection bias between radio-active and radio-quiet objects. This research should help clear statistical questions surrounding the optical selection criteria for radio-quiet candidates.Not only radio-loud and -quiet, but also (especially) optical biases. This work will also improve our confidence in the AGN model, per my earlier post (http://www.physicsforums.com/showpost.php?p=240441&postcount=20).

Nereid

Jul10-04, 06:30 PM

Nereid, I'll willingly play the devil's advocate on this one. What if you have a cloud of smaller objects that are essentially captivated and falling directly into the larger object without significant orbital motion? Some objects will be redshifted, a smaller number will be blueshifted (because we will miss a portion of those objects due to obscuration by the host galaxy) and those objects that are dropping into the host galaxy on a plane perpendicular to our line of sight will exhibit the same redshift as the host.

Assuming NO orbital motion (direct infall only), and an obsuration of blueshifted objects of 10%, and non-discrepant redshift due to perpendicular orientation of infall paths of some objects (maybe another 10%), we still have a probability of less than one in 512 that all the small objects that surround the massive host will exhibit an excess redshift relative to the host. This is a far cry from 8% (1/12) cited in Nemnam-Terzian.

I believe that these are very fair, conservative estimates. I don't want to paint you into a corner and try to make you defend the Newman-Terzian paper, but what do you think of their paper?I think the paper is excellent. (I haven't been able to find an on-line version of the original Arp paper, so my comments must be rather tentative).

The main gulf seems to be the underlying assumptions; Newman & Terzian (N&T) make none whatsoever about the dynamical relationship among the Local Group objects; you (and presumably Arp) assume a single, gravitationally domanating object (M31).

N&T actually highlight this gulf, before doing their own analysis: "The simple dynamical picture presented by Arp is inconsistent with the observed disposition of the galaxies of the Local Group. There is no dominant galaxy per se, and the dynamical picture presented by the group's members is highly complex - indeed, the potential for chaotic behavior in this dynamical system cannot be excluded."It's hard for me to understand how the Newman-Terzian paper was published with such a very glaring basic statistical error.My guess is that, as they stated their assumptions clearly, there was no 'glaring basic stastical error'; perhaps we could move the debate to the question of the likely dynamical status of the Local Group?

Since N&T, new LG members have been identified, and (maybe) better redshifts obtained for those members. Using this source (http://www.seds.org/messier/more/local.html), we find the following members of the M31 sub-group: M32, M110, NGC 147, NGC 185, And I, And II, And III, And IV, Pegasus dwarf, Cassiopia dwarf, and And VIII (And IV maybe?; this site was last updated in 2003, before And9 was discovered). Here are the stated relative velocities (cf MW centre, in km/s) of those (not all M31 sub-group members have published redshifts, apparently):
M31: -59
M32: +35
M110: -1
NGC 147: +89
NGC 185: +39
And VIII: -250

So, 4 have a +ve RV cf M31's, and 1 a -ve RV. Even if this sub-group could be shown to be quite isolated (it's not at all; M33 and the Milky Way must have a significant influence, without even looking at any possible DM concentrations, or high velocity gas clouds), 1/5 isn't all that improbable.

(Next, MW sub-group; if I have time).

turbo

Jul10-04, 11:13 PM

Hi Nereid!

As you know, when I posted my critique of the Newman-Terzian paper, I did not dispute the observations quoted by either side. I kept my post focused on the statistical methods employed by both sides. The problem with the Newman-Terzian paper is that the authors stripped the gravitational influence of the largest body out of the analysis (which was a central point in Arp's presentation) and then presented the 12-body problem as a simple case of ordination. This is the best way to understate the odds that all eleven small companions would be reshifted relative to the largest body. The astronomical community gave this paper free pass, although any sharp 7th grader would have trouble letting it by.

In essence, the authors presented Arp's system of 12 bodies as a simple set of equivalent items, ignoring the gravitational influence of the (FAR more) massive body then said "there is a 1/12 chance that the largest body will be the least redshifted". This is VERY wrong. It is like a pair of cops barging into a room looking for a bank robber and finding eleven pre-schoolers and one adult with stain from a dye-bomb on him and concluding "there is a one in twelve chance that this is the person who robbed the bank".

As you point out, the authors state that "the dynamical picture presented by the group's members is highly complex - indeed, the potential for chaotic behavior in this dynamical system cannot be excluded". That statement does not excuse them from ignoring basic probability, however. In a chaotic environment, should we expect to find ALL the smaller bodies to be redshifted with respect to the largest body "some of the time", "most of the time", or "all of the time"? Chaotic behavior in complex systems permits short-term anomolies (even very unlikely ones) but it does not trump probability in the long term or over multiple samples.

To summarize again, N-T did not dispute Arp's redshift characterizations of either of the galaxy groups (2 groups, each with eleven companions around more massive galaxies) nor did I. They challenged Arp's statistical methodology, and they presented alternative "analyses" that were very badly flawed, even cynical. Arp-bashing is popular and easy, but I think you would have trouble getting the authors to defend that paper today.

Chronos

Jul11-04, 01:54 AM

Nereid, I was beginning to think I was alone in my interpretation of the NT paper. I believe it is very relevant and entirely valid. I have not heard anyone claim, and have no reason to dispute, that Mr Arp is other than a well intentioned and honorable man. I just think he is wrong and can't admit it. My objection to Arp et al is in using mass media in a transparently lame attempt to convince the public that flawed assumptions and flawed math are attributable to a great conspiracy by 'mainstream scientists' to suppress their 'discoveries'. True science is hard enough without people appealing to public opinion to support their failed theories. When peer opinion, and observational evidence is overwhelmingly against you, the honorable thing to do is admit it. Einstein did. As it turns out, he may not have been the least bit wrong. His concept of a 'cosmological constant' is very much alive these days. But he had enough humility and respect for his peers to admit he did not have the math to prove it.

Chronos

Jul11-04, 02:27 AM

Turbo, please elaborate. In what way is Arp's statistical analysis more 'correct' than NT's? NT made no assumptions about system dynamics, Arp did. Arp offered no proof of this basic assumption. It is therefore suspect, at best, and mostly contraindicated by observational evidence. I am not a dogmatic fool, but, I am a sucker for observational facts and supporting math. So, from my reference frame, the Arp assumption is invalid.

Nereid

Jul11-04, 05:14 PM

I didn't cite Stephan's Quintet as an example of interaction between discordant-redshift galaxies. I think the high resolution imagery from HST put that one to bed years ago. There are, however, examples of apparently-interacting objects with very discordant redshifts, one of which I mentioned in one of the first posts in this thread.It was meteor, in this post (http://www.physicsforums.com/showpost.php?p=240470&postcount=21)

Good to know that surface-brightness fluctuations are accepted as a valid measure of distance (independent of redshift).

turbo

Jul11-04, 05:17 PM

Turbo, please elaborate. In what way is Arp's statistical analysis more 'correct' than NT's? NT made no assumptions about system dynamics, Arp did.

Arp's "assumption" about system dynamics is one that you or I would make intuitively. It is gravity and orbital motion. In a cluster of galaxies, the group's members will exhibit motions relative to each other. The members will move along geodesics in curved space-time - elliptical orbits that conserve angular momentum. This is a given. The geodesics along which these orbits lie are functions of the masses and positions of the members of the group.

Remember that the largest objects in the group will be less-perturbed than their smaller neighbors, but they too will exhibit some proper motion relative to their neighbors. To envision this, remember that the earth is perturbed by the mass of the moon as it orbits, just as the sun is perturbed by the mass of the orbiting earth.

Now, let's take the M81 system - 13 galaxies in all, with M81 being by far the most massive. M81's companion galaxies cannot just float out in space with no angular motion relative to their more massive host - with no angular momentum, they would simply follow the path of least resistance (inward radial path) toward the gravitational center of the system and be swallowed up by their huge host.

In a more Newtonian view, we say that the objects in a gravitational system orbit around their common center of mass. In a system where one large massive galaxy dominates, the common center of mass is very near (or in) the large host, and its proper motions relative to the small companions are rather small, while the motions of the smaller objects relative to the host are much larger. Observationally, the small companions of M81 must have proper motion relative to M81. Some should be moving away from us, some toward us, and some may be moving more or less perpendicular to our line of sight. This should result in somewhat fewer than 1/2 of M81's companions being redshifted relative to the host. Arp used a simple 50:50 ratio, which while somewhat inaccurate, was generous to his critics since it should have biased the results against his theory a bit.

As I have mentioned several times in this thread, Newman-Terzian made a HUGE assumption that everybody seems to overlook. If you will read the N-T paper, you will find it on page 1, section 2 Combinatorial Considerations. The authors *assume* a fully random distribution of motion among cluster members with no dynamical pattern whatsoever. They excused this by saying in essence "the system is too complex for us to normalize" so they entirely threw out all the laws of Newtonian gravitational theory and Einstein's space-time field. By doing so, they treated M31 as if were no more massive or gravitationally influential than the Large and Small Magellanic Clouds. That is patently absurd. Newman&Terzian smugly refer in their paper to "the error in Arp's combinatory approach" - there is high irony there.

Notice that they only discussed the M31 cluster, so they could claim that the closer relative masses of M31, MW and M33 hopelessly confuse the dynamic of the cluster. The situation with the M81 system is far more straightforward, though, with a very massive central galaxy. If we look out at the M81 cluster, we should expect to find the smaller companions to have measurable proper motion relative the host galaxy. Again some should be blueshifted, some should be redshifted, and some could be neutral due to orbital inclination or present-day orbital position.

Now do you see where N-T is flawed? They make the very radical assumption that the companions of a massive host galaxy do not need to have proper motion relative to the large galaxy, and that they can treat the largest galaxy as if it had no more gravitational influence than the smallest companion. This is wrong, and Einstein and Newton both would tell them so in an instant. The universe is in constant motion, and astronomical bodies follow geodesics in space-time (or orbits if you prefer) that are determined by the mass, speed, and location of the bodies. The largest body or bodies in their neighborhood contribute the bulk of the space-time distortion (or gravitational pull, if you prefer Newton). For those companion galaxies to exist at all, they MUST be exhibiting some angular proper motion relative to the host galaxy - otherwise, they would have fallen into the host long ago.

By assuming that the members of the M81 group do not need to exhibit any classical orbital motion relative to one another (a very radical assumption, again), N-T were then able to treat the redshift excess of the companions as a problem of ordination, saying there is a one in twelve (8%) chance that the largest object will be the least redshifted. Their paper completely ignored gravitional interaction and causation. It was the only way that they could use non-substitutive ordination to arrive at their very low probability that all the companions would be redshifted relative to their hosts. Their math is very basic, accurate, and easy to follow but the statistical methods they applied are entirely inappropriate to the data.

Arp offered no proof of this basic assumption. It is therefore suspect, at best, and mostly contraindicated by observational evidence. I am not a dogmatic fool, but, I am a sucker for observational facts and supporting math. So, from my reference frame, the Arp assumption is invalid.

Again, Arp's basic assumption was that galaxy clusters have to obey the classical laws of physics with regard to gravitation, motion, etc. This is not something that normally has to be stated in the introduction of any astronomy paper, so its absence should not be troubling. Newtonian gravitation and Einstein's space-time field theories are pretty well-established, so you'll have to have a pretty good reason to arbitrarily declare them invalid. The observational evidence DOES show that the companion galaxies are redshifted relative to their hosts. Arp did not make those observations - that was done a very long time ago. The observational evidence alone cannot/should not invalidate Newton/Einstein either, but there is something that does need to be re-examined - our understanding of the causes of redshift. Arp simply made the observation that if we expect the members of galactic cluster to behave in accordance with what we know about gravitation, some companions should be moving toward us and some should be moving away. The fact that all of M81s comapanions are redshifted relative to it means that either they are all somehow preferentially running away from us for some reason, OR there is something about redshift that we do not understand. It is a very simple concept. If smaller galaxies in clusters are preferentially redshifted relative to the largest members, either the Earth is at the most special place in the universe (forbidden by all credible cosmologies) OR there is something other than currently accepted causes (cosmological expansion, doppler shift, and Einstein's gravitational field effect) that must be responsible for the excess redshift.

Here's the math: if there is a 50:50 probablility of finding an object in a particular state, and you sample 11 such objects, the math is multiplicative. 1/2 x 1/2 x1/2.... etc. With eleven objects with equiprobable states, that comes out to 1/(2 to the eleventh power) or 1/2048. Quite a far cry from 1/12. I used the number 11 as the number of objects because that is how many objects were included in the "analysis" that N-T gave the M31 group. There are actually 12 companion galaxies in the M81 group giving only one chance in 4096 that all of them will be redshifted relative to the host. They all are, and they all have significant recessional velocities.

Here is a link to a page on the M81 group with recessional velocities listed.

http://www.seds.org/messier/more/m081gr.html

I know I sound like a broken record talking about this N-T paper, and I wish that I could explain the basic logical flaws in it more clearly, because I seem to be missing the audience. I'll glady follow up (at the risk of boring everyone to tears!) if there are questions.

Nereid

Jul11-04, 05:22 PM

Chronos

Jul11-04, 05:54 PM

Here is link to Arp paper referenced in NT paper

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1994ApJ...430...74A&db_key=AST&high=3cf96e067121063

turbo

Jul11-04, 06:11 PM

Can you give us a link to an online copy of the 1994 Arp paper? Without reading what N&T were responding to, it would be better for me to say little more (re content).

Sure! I found it pretty easily and I had foolishly assumed that everyone interested in this thread had reviewed it. The "fingers of God" distribution of galaxies in the Virgo cluster, the K-effect (intrinsic redshifts of supermassive young stars in our own galaxy, SMC, and LMC), and other arguments for intrinsic redshift are presented in the paper, but the real giant-killer is the very simple straightforward examination of already-existing redshift measurements in the M31 cluster and the M81 cluster.

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1994ApJ...430...74A&db_key=AST&h igh=40f19ad6db11758

turbo

Jul11-04, 07:53 PM

Thank you Chronos, a most interesting read.

This paper should allow us to put several 'association' and 'quantized z' hypotheses to sleep. Does anyone know if any serious astronomers in either of those camps are still banging those drums?

Now that some SDSS results are in the public domain, perhaps a similar piece of research could be done using those? The good news is that SDSS uses a completely different method to select objects for specta than 2dF did, so if similar analyses of the two datasets yield similar results there'll surely be no place to hide!

I particularly liked the approach taken here: a proponent in one camp suggests a method of analysis, and a neutral third party carried out the work, using publicly available data. What's good? The method and expected outcomes were clearly defined BEFORE the work was done, and the datasets are in the public domain (you don't like the conclusions? there's nothing at all stopping you from performing your own analyses!)

Yes, thank you for the link Chronos! Nereid summed up my feelings pretty well. As we discussed earlier (in this thread, I think) I feel that there is solid observational evidence for intrinsic excess redshift, but I am philosophically (intuitively, more likely) repelled by the thought that redshift might be quantized. I am prepared to accept a mechanism for excess redshift that can produce a smooth continuum of values, but quantization of redshift values in objects as apparently violent and energetic as quasars just goes against my grain. Please note the very precise reasoning (including all relevant maths) for my position. :smile:

Nacho

Jul12-04, 05:25 AM

Arp and his ideas have been one of my favorite readings, but I've kinda lost contact since some of the observations of the last few years.

Good to see he's still out there "giving 'em hell"!

Nereid

Aug6-04, 08:03 PM

Sure! I found it pretty easily and I had foolishly assumed that everyone interested in this thread had reviewed it. The "fingers of God" distribution of galaxies in the Virgo cluster, the K-effect (intrinsic redshifts of supermassive young stars in our own galaxy, SMC, and LMC), and other arguments for intrinsic redshift are presented in the paper, but the real giant-killer is the very simple straightforward examination of already-existing redshift measurements in the M31 cluster and the M81 cluster.

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1994ApJ...430...74A&db_key=AST&high=40f19ad6db11758Been meaning to post a reply to this for quite a while now. Thanks Chronos and turbo-1 for the links.

The Arp paper was richer than turbo-1's build up implied (to me anyway). For example, it contained a section ("Comments on Galactocentric Corrections to Heliocentric Spectral Shifts") that introduces an important consideration which makes the LG a much more difficult group to study (in terms of Arp's thesis). In fact, given how massive the Milky Way is (wrt M31), and the lack of any data (?) on transverse motions, I wonder how any conclusion about the LG could have been drawn from the data Arp had available at the time.
Arp 0, N+T 0.

So if just the M31 sub-cluster (my term, not Arp's) is examined, then there are surely too few data points in Arp's paper to make any kind of case.
turbo-1 0.

What about the M81 group? N+T's paper didn't examine this, and Arp's didn't give a table of values, just a figure (with 11 group members, other than M81). In this case, the galactocentric corrections are much less problematic, and the measured radial velocities apparently accurate enough. Interesting case.
Arp 1.

Then we have the fingers of god. I didn't read this part too carefully, partly because it's obvious that there's far, far more high quality data now than when Arp wrote in 1994.

Which brings me to an important point. Arp’s paper is now 10 years old, and reading it one has a faint sense of surprise … only 25 LG members (cf 45+ recognised today); some tough calls about LG membership (cf the ease with which stars can be resolved in target galaxies today); no mention of high velocity clouds, star streams, etc; how the determination of redshifts then were apparently a rather big undertaking (cf 2dF and SDSS, which routinely took/take hundreds in one go); …

Surely a month or two’s work, mining some of the existing, public astronomical databases could increase the amount of data relevant to Arp’s thesis by an OOM or two?

turbo

Aug7-04, 12:02 PM

So if just the M31 sub-cluster (my term, not Arp's) is examined, then there are surely too few data points in Arp's paper to make any kind of case.
turbo-1 0.
Didn't you mean turbo-1 1? I pointed out that the closer relative masses of MW and M31, etc made the local group problematic - which is WHY N-T chose it to try to refute Arp. If they had chosen the M81 group, they could not have made any logical argument against Arp's thesis, or at least they wouldn't have been able to slip their "non-substitutive ordination" trick past the referees (I hope :yuck:). I explained why N-T decided to use the local group at least a couple of times in the thread. Perhaps I wasn't clear.

What about the M81 group? N+T's paper didn't examine this, and Arp's didn't give a table of values, just a figure (with 11 group members, other than M81). In this case, the galactocentric corrections are much less problematic, and the measured radial velocities apparently accurate enough. Interesting case.
Arp 1.
Yes, very interesting indeed. If all of M81's neighboring galaxies have decided to run away from Earth, we must be a scary bunch! Seriously, no reputable cosmological model permits us to occupy such a priviliged location in the Universe, not only with respect to the apparent preferential recession of M81's companions, but also with respect to the much larger "Fingers of God" artifacts that show up in our redshift data. To those not familiar with this, just Google "Fingers of God" and you will find otherwise rational people discussing the artifacts, with some really clever explanations as to how they can be explained away. (You'll laugh! You'll cry! :smile:) More "epicycles" to tack onto our cosmology to hold it together... The artifacts in the data are real, but they are not due to "streaming effects" etc, etc (which put us back in the forbidden favored-observer position), but are instead due to a deficiency in our understanding of the causes of redshift. The Cosmus site
http://astro.uchicago.edu/cosmus/projects/fog/
calls these artifacts "glitches" and has done us all a favor by removing them from their fly-through visualization of the SDSS data. How nice of them. There is something causing these apparent redshift differentials that we do not fully understand. Since understanding and accurately measuring redshift is a vital tool in cosmology, you'd think that we would pour funding into discovering the deficiency in our understanding of redshift that allows the "Fingers of God" to show up in our redshift maps. Instead, those scholars simply "retouched the images" to make those disturbing artifacts go away. So sad. That is not science, it is the negation of science in the protection of orthodox beliefs. Edwin Hubble is probably spinning in his grave. Redshift=distance has been a very handy approximation, but it is only a tool, not an immutable law of the Universe. It's time to refine the model.

We KNOW that the artifacts exist in our redshift maps (SDSS data) and we KNOW that the F.O.G. cannot be due to the actual distributions of the galaxies. Logically then, our measurements of redshift cannot be strictly interpreted to equate to distance. Case closed. What other causative factor(s) can there be for the redshift differentials? That is one of the biggest questions still hanging...and cosmology is due for a thrilling ride when enough people start asking the right questions.

When the sacred redshift=distance has to be modified (and it WILL:wink:), it will put a lot of balls in play, including the Big Bang, cosmological expansion, the nature of quasars, "missing mass", etc, etc. Now would be a great time to be starting out as a student of Physics/Astronomy/Cosmology because the field will be wide-open for bright open-minded researchers.

Nereid

Aug7-04, 05:22 PM

Quite a response turbo-1! Just to get back quickly on a couple of things:

- M81 group: if 20 members of the LG have been added in ~10 years (nearly doubling its membership), how many 'unseen' members of the M81 group are there? How much has our understanding of this group advanced in a decade? Some examples: is it really an isolated group (maybe there is an attractor)? what is the distribution of dwarf galaxies (perhaps these really do matter in the group, being the tip of very large DM icebergs)?

- fingers of god: I don't think that you did justice to the consensus view of these. In a few words, if cluster members are gravitationally bound, they will have to/from Earth motions (observed as redshifts) reflecting their 'orbits' in the cluster. If the cluster is relaxed, we can measure those motions, apply the virial theorem, and get an estimate of the total mass of the cluster. The more massive the cluster, the greater the dispersion of redshifts around the cluster (weighted) mean. These dispersions will show up, on 2dF or SDSS sky maps, as fingers of god. None of this is a big secret; in fact, these cluster dispersion measures of cluster mass are one of the sets of observations which imply lots of dark matter in clusters (and one which is, IIRC, inconsistent with MOND).

Arp asserted that there is a considerable excess of 'from' motion (higher redshift than the cluster mean) than 'to' motion (lower redshift), at least for the Virgo cluster. I said that Arp's assertion should be able to be tested using the huge amount of data that we now have.

In the next post, I will propose a research project, for you and me and at least one other person (of course, all PF members are welcome to join), to do a simple test of Arp's fingers of god assertion.

turbo

Aug7-04, 06:44 PM

- M81 group: if 20 members of the LG have been added in ~10 years (nearly doubling its membership), how many 'unseen' members of the M81 group are there? How much has our understanding of this group advanced in a decade? Some examples: is it really an isolated group (maybe there is an attractor)? what is the distribution of dwarf galaxies (perhaps these really do matter in the group, being the tip of very large DM icebergs)?
What kind of attractor could pull M81's companions from its grasp? There is no visible object in that direction that serves the purpose, and the gravitational force of the attractor would have to be huge. I think we can discount that one, unless it is a huge well of "dark matter" located very near the opposite side of M81 from us. (another preferred-observer situation)

- fingers of god: I don't think that you did justice to the consensus view of these. In a few words, if cluster members are gravitationally bound, they will have to/from Earth motions (observed as redshifts) reflecting their 'orbits' in the cluster. If the cluster is relaxed, we can measure those motions, apply the virial theorem, and get an estimate of the total mass of the cluster. The more massive the cluster, the greater the dispersion of redshifts around the cluster (weighted) mean. These dispersions will show up, on 2dF or SDSS sky maps, as fingers of god. None of this is a big secret; in fact, these cluster dispersion measures of cluster mass are one of the sets of observations which imply lots of dark matter in clusters (and one which is, IIRC, inconsistent with MOND).
There is no big secret, here, but there the "consensus view" is full of misdirection and apologia regarding these artifacts. There is no doubt that the Fingers of God distribution of galaxies in the SDSS data exists. There is considerable differentiation, however, in the explanations regarding how the artifacts arose, and the "proper" methods by which they should be filtered out. I will not attempt to explain away or refute every "epicycle" that has been floated to try to massage these artifacts away. The F.O.G. are in the data and have not been adequately explained.

I suggest that the SDSS data is accurate. Nothing more. Given that the data is accurate, and given that the Earth cannot be at the center of the Universe (in the sense of a preferred reference point) we must come to the understanding that our redshift data does not accurately describe the distribution of the galaxies observed. That is a given. You say that orbital motions of galactic clusters will distort their redshifts to stretch the apparent shape of each cluster so that it appears pointed toward us. Do you see a parallel with the "shape" of the M81 group (M81 "closest to us", companions "streaming away")? This should be a cause for reflection.

Arp asserted that there is a considerable excess of 'from' motion (higher redshift than the cluster mean) than 'to' motion (lower redshift), at least for the Virgo cluster. I said that Arp's assertion should be able to be tested using the huge amount of data that we now have.

In the next post, I will propose a research project, for you and me and at least one other person (of course, all PF members are welcome to join), to do a simple test of Arp's fingers of god assertion.
I have been working about 60 hours a week on a very large project that is critical to my company, and I see little respite for the near term (another 3 months or so), so I hope the proposed project is not time-intensive. I have had a few moments today to post, but worked most of the day, and expect to have to work all Sunday, as well. Bleah! :yuck: I welcome the prospect that others may join in the investigation into the source of the F.O.G. I must say up-front, however, that some *very* competent folks have been working for years to make those Earth-centered radial streaks in the SDSS data "go away", with varied degrees of success.

The artifacts are in the data, and rather than invent mechanisms to refute them, we would be better served by an open-minded effort to discover what deficiency in our understanding of redshift allows these distortions to exist.

turbo

Aug8-04, 07:34 AM

- fingers of god: I don't think that you did justice to the consensus view of these. In a few words, if cluster members are gravitationally bound, they will have to/from Earth motions (observed as redshifts) reflecting their 'orbits' in the cluster. If the cluster is relaxed, we can measure those motions, apply the virial theorem, and get an estimate of the total mass of the cluster. The more massive the cluster, the greater the dispersion of redshifts around the cluster (weighted) mean. These dispersions will show up, on 2dF or SDSS sky maps, as fingers of god. None of this is a big secret; in fact, these cluster dispersion measures of cluster mass are one of the sets of observations which imply lots of dark matter in clusters (and one which is, IIRC, inconsistent with MOND).OK, a couple of difficulties with the consensus view of the FoG. For the reshifts of these galaxies to be smeared radially as they are in the data, their orbital velocities need to be very large - somewhere on the order of 1000 km/s. To produce those velocities, the central galaxies would have to be VERY massive (here comes the elusive dark matter again).

Another problem: as you pointed out, we would expect the smaller glaxies to swarm around the largest galaxy in each cluster, some moving toward us and some away from us to produce the radial smearing. Why don't we see that orbital motion expressed in the M81 cluster? As you can see in the Tully catalog quoted here (the basis for Arp's calculations):
http://www.seds.org/messier/more/m081gr.html
M81's companions are all preferentally streaming away from us. The shape of the cluster would seem to be elongated (with M81 closest to us and pointing at us), but this effect is not caused by orbital motions of the small galaxies. The orbital motions of these small galaxies must contribute to their measured redshifts, but that contribution is overwhelmed by *something* that gives them much more excess redshift and makes them appear to be all receding from us relative to M81.

Another little wrinkle: on larger scales, the Kaiser Effect would dominate, causing the clusters to look flattened, not elongated. It is suggested by conventional cosmologists that this effect only occurs on supercluster scales, but it's evident that there is a lot of "wiggle-room" in the consensus view.

rob_we

Aug9-04, 01:56 PM

I have two questions to anyone who knows..

First: Are there known interacting systems with more or less equal mass with a redshiftdifference like this (M51)

Second: Are there known interacting systems like M51 consisting of a bigger and a smaller system with no redshift difference?

thanks in advanve

Rob :)

turbo

Aug9-04, 05:47 PM

Are there known interacting systems like M51 consisting of a bigger and a smaller system with no redshift difference?
Rob :)
If I can be permitted to modify your question just a bit, "are there known interacting systems like M51 in which the smaller companion has LESS redshift than the dominant galaxy?" This should happen about 50% of the time, if redshifts are caused only by cosmological distance (due to expansion) and by the proper motion of the associated galaxies.

ADDED: Actually, the smaller companion should have more redshift less than 50% of the time. There will be times when the proper motion of the small galaxy is perpendicular to our line of sight, and therefore should exhibit no redshift differential. The instances when the redshift of the smaller galaxy is less than or equal to the host should therefore outnumber the instances when the smaller galaxy has the greater redshift. END OF ADDITION

If the small companions are more redshifted than their hosts a statistically significant percentage of the time, then there must be something we don't yet understand that is producing the excess redshift.

Nereid

Aug12-04, 08:25 AM

Welcome to Physics Forums rob_we!

Your last post was quite interesting, but did you know that we have an entire section devoted to the exploration of theories such as yours? It's called Theory Development.

Perhaps Phobos or Janus could move rob_we's post there, as the start of a new thread (with a link back to this thread)?

selfAdjoint

Aug12-04, 10:18 AM

rob_we's post has been moved to Theory Development.

turbo

Oct18-04, 08:37 PM

Now that some SDSS results are in the public domain, perhaps a similar piece of research could be done using those? The good news is that SDSS uses a completely different method to select objects for specta than 2dF did, so if similar analyses of the two datasets yield similar results there'll surely be no place to hide!Hi Nereid! I thought you might want to see this. I have been quite uncomfortable with the concept of "quantization" of quasar reshifts, but the quasars pulled out of the SDSS data do seem to cluster. Any comments?

http://citebase.eprints.org/cgi-bin/citations?id=oai%3AarXiv%2Eorg%3Aastro%2Dph%2F0409 025

Chronos

Oct19-04, 01:55 AM

Hi Nereid! I thought you might want to see this. I have been quite uncomfortable with the concept of "quantization" of quasar reshifts, but the quasars pulled out of the SDSS data do seem to cluster. Any comments?

http://citebase.eprints.org/cgi-bin/citations?id=oai%3AarXiv%2Eorg%3Aastro%2Dph%2F0409 025I would be reluctant to cite that paper as authoritative. He makes a number of assertions that are, at best poorly explained; e.g.;

1] "If high-redshift quasars are ejected from the nuclei of low-redshift galaxies, as some have claimed, a large potion of their redshift must be intrinsic [non-Doppler]."
a) What about high-redshift quasars that cannot be associated with low-redshift galaxies [which are intrinically much brighter than their ejected offspring, according to this paper]
b) Non-Doppler? It has generally been assumed that redshifts exceeding z=1 are exclusively non-Doppler. What mechanism explains Z>2 intrinsic redshifts? Gravity?

2]"Since the term local model can be misleading, by implying that all quasars are local, the term decreasing intrinsic redshift model (DIR model) will hereafter will be used"
a) While the term 'DIR model' is indeed used thereafter, a description of the 'model' is conspicuosly absent, aside from claiming it mostly makes the same predictions as the standard model.

Upon checking, I concluded Bell has a history of writing almost exclusively in support of intrinsic/quantized red shift and QSO ejection models, and makes generous use of speculative assumptions.

turbo

Oct19-04, 08:34 AM

I would be reluctant to cite that paper as authoritative. He makes a number of assertions that are, at best poorly explained; e.g.;Ignore his assertions for now. Just look at Figure 1 for a while. The clustering of the SDSS quasar redshifts should raise questions. Is there any mechanism you can think of that would cause the clustering at these redshift values? In past studies, such clustering has been attributed to faulty selection criteria, sensitivity/binning artifacts, etc.

1] "If high-redshift quasars are ejected from the nuclei of low-redshift galaxies, as some have claimed, a large potion of their redshift must be intrinsic [non-Doppler]."
a) What about high-redshift quasars that cannot be associated with low-redshift galaxies [which are intrinically much brighter than their ejected offspring, according to this paper]
b) Non-Doppler? It has generally been assumed that redshifts exceeding z=1 are exclusively non-Doppler. What mechanism explains Z>2 intrinsic redshifts? Gravity?He made the point quite clearly that "Hubble flow" and "Doppler" effects, caused by cosmological expansion and proper motion, respectively, cannot explain the clumping of the quasar's redshifts around certain values. Not everybody assumes that redshifts exceeding z=1 are "exclusively non-Doppler".

2]"Since the term local model can be misleading, by implying that all quasars are local, the term decreasing intrinsic redshift model (DIR model) will hereafter will be used"
a) While the term 'DIR model' is indeed used thereafter, a description of the 'model' is conspicuosly absent, aside from claiming it mostly makes the same predictions as the standard model.He is citing an evolutionary model for quasar production proposed by Arp, Burbidge, et al. Quasars are ejection phenomena. They start out at high redshift and evolve to lower-redshifts. This is a model of quasar evolution only, not an over-arching cosmological model.

Upon checking, I concluded Bell has a history of writing almost exclusively in support of intrinsic/quantized red shift and QSO ejection models, and makes generous use of speculative assumptions.You will find that Arp and Burbidge (and others) write about intrinsic redshifts and quasar ejection. That does not make them wrong. Their model makes a lot more sense than the standard model, which places quasars very far away based on their redshifts.

Believers in the standard model think the redshift of quasars is due to cosmological expansion, which places them at huge distances. This causes quasars to have properties that are a lot more troubling than intrinsic redshift, including:
1) More energy output than a hundred galaxies
2) Very highly organized and powerful even in the infancy of the universe (a problem for the heirarchical model)
3) Short-term output fluctuations that limit their size (smaller than the diameter of our solar system)
4) Some ejection jets that exhibit apparent superluminal motion
All of these problems go away if quasars are relatively nearby objects with intrinsic redshift. Is the Hubble redshift/distance relationship so sacred that we must accept monsters with these problems to prevent its violation?

Questions: If a black hole is slingshotted out of the center of a galaxy and starts gobbling matter, what would it look like? Would it look very energetic? If its accretion disk was initially very small and close to its event horizon, would the light from that disk be very redshifted? Would the redshift of the light from that disk gradually decrease as the disk gets larger and extends farther from the intense gravity well of the black hole? These questions lead to a very over-simplified model of quasar evolution that is nevertheless a lot more palatable than the standard model (see problems 1-4 above).

I am still not comfortable with quantization or preferred redshift values, but Figure 1 is pretty compelling. If the redshifts of quasars are entirely due to cosmological expansion, we should see a smooth distribution of quasar redshifts, but here is the SDSS sample of over 5000 quasars, and their redshifts are clumped in a regular fashion. Is there any way to explain this clumping without invoking intrinsic redshifts? If so, I would like to hear about it. :rolleyes: