SDSS Quasars & Cosmology: Challenges to Current Models

[Nereid]

what does 'The luminosity function curve slope changes fairly abruptly after redshift z~3' mean?

The LF (luminosity function) is the (2D) relationship between intrinsic luminosity and volume density; crudely, how many quasars are there, per cubic Mpc (megaparsec), in the intrinsic luminosity range [M_i, M_i+1], over all M_i? In the Strauss video (and paper that it largely comes from), the vertical axis is logarithmic in Mpc^-3 mag^-1, and goes from ~10^-9 to ~10^-6 (for z>2 quasars). The horizontal axis (absolute magnitude, representing luminosity) goes from ~-24 to ~-29 (or perhaps -30).

(if you'd like a quick tutorial on 'magnitude', 'luminosity', etc, just holler)

For quasars, the current paradigm is to fit them with 'a broken power law', meaning that on the graph/plot/chart I have described, fitting two straight lines, one for the high-luminosity objects, and one of the lower luminosity objects, with a break-point (where the two line intersect). For the quasars under discussion here (those with z>3, and observed in SDSS DR3), the fainter-luminosity line is not so relevant.

The slope of the LF line (for higher-luminosities) is estimated by making a fit to the datapoints (in some statistical sense); such estimates are made (in the Strauss video) at z = 2.01, 2.40, 2.80, 3.25, 3.75, 4.25, and 4.75, by some binning of the data. Formal (1σ) error bars are calculated. When the fitted slopes are plotted, against z, they show a (z) trend, from ~-3.2 (z<3) to ~-2.1 (z=4.25), with the datapoint at z = 4.75 as an outlier (and with huge error bars). For z<3, the fitted slopes have values ~-3, with some scatter, but more or less within the error bars.

And that's it.

Perhaps you'd be interested in what astronomers interpret this set of (very substantially processed) material means?

If so - or if any other reader is interested - I'd be happy to try to explain ...

 

[turbo]

To add to what Nereid has offered here, there are some substantial error-bars on the observations at the high-redshift end of this curve. When you are observing objects at the limits of detectability (with your 'scope/sensors) and you have to rely on single-band observations and poorly-constrained spectra, things can get dicey. Still, the SDSS folks are the gold standard for this kind of survey work.

 

[turbo]

More later, though family concerns intervene.

 

[Nereid]

Good idea.

I'll go listen to what Strauss actually said (in the video), and write a transcript (FWIW, I think, again, your summary is either too brief or has missed something vital wrt your claims).

It starts at ~20:15 minutes, and slide 36:

"A similar [game?] that Pentericci et al. have done using the VLT, they've taken the near-IR spectra, now not of ... this is a sample that you can see is not exclusively of the very high redshifts, going from redshift 4.7 to 5.8, and in this case the game is to take spectra of the rest-frame around 2800Å, so this emission line of magnesium and also iron, and there's no obvious difference in the relative strengths, or for that matter the absolute strengths, of iron and magnesium relative to lower redshift. Magnesium and iron are generated by different types of supernovae and one might imagine that one finds differences as one starts probing back to close to the big bang. No such differences have been found yet."

"Pentericci et al. 2005 VLT near-IR spectra"? I draw a blank on that; perhaps some other reader can track it down*?

Then I'll check what the paper that this presentation is largely from actually says (and I'd really appreciate it if you were to do the same ... PF's guidelines are pretty unambiguous about what sources should be used in threads like this ...).

[...]

Stay tuned for the next exciting episode!

* this illustrates well a shortcoming of relying on primary sources which are other than published papers (or at least preprints on arXiv); it can be difficult (or worse) to actually find the source of the presented data!

 

[Chronos]

Any discrete object observable at z ~ 6.5 is obviously a freak - i.e., uncommonly bright. The fact they exhibit unexpected observational properties is not exactly - unexpected. Is high metallicity in the early universe forbidden by LCDM? I think not. I don't even think it is relevant given our very crude understanding of nucleosynthesis. Who is to say these distant bodies operate on the same principles as more local 'quasars'? Could they be a unique class of objects that only existed in the very early universe? All indications suggest the very early universe was more energetic and dynamic than it is today. The SDSS observations are fascinating, but, nowhere near sufficient to justify abandoning theoretical models that have been crafted from a much larger number of much better observations. I am unwilling to accept philosophy as a legitimate rival to the scientific method.

 

[Nereid]

Pentericci et al. 2005 VLT near-IR spectra doesn't exist!

"Pentericci et al. 2005 VLT near-IR spectra" doesn't exist!

Well, I can't find it.

Assume - until someone does dig it up - that there is no such paper, what then?

Well, it rather pulls the rug under turbo-1's claims, doesn't it? Or at least the claim about the metallicities of the stars in the high-z (~>6.5) quasars, and how there is no metallicity evolution in quasars ...

Of course, turbo-1 was only summarising what he heard Strauss say in that video ... but then that video has a very specific provenance, and Strauss' intended audience* no doubt were well used to the conventions for presentations such as this ... including that it's provisional, and that the actual published papers are really the only reliable sources (reflected in PF's guidelines too).

An interesting conclusion, n'est pas?

* and, no doubt, most of his actual audience in Princeton that day

 

[matt.o]

"Pentericci et al. 2005 VLT near-IR spectra" doesn't exist!

Well, I can't find it.

I think it should be Pentericci et al. 2002, AJ, 123, 2151. See the http://adsabs.harvard.edu/abs/2002AJ...123.2151P"

 

[turbo]

The results are indistinguishable from those of lower redshift quasars and indicate little or no evolution in the metal abundances from z  6 to 2. The line ratios suggest supersolar metallicities, implying that the first stars around the quasars must have formed at least a few hundreds of mega years prior to the observation, i.e., at redshifts higher than 8.

Thank you, Matt.o

 

[turbo]

and show no evolution with redshift - turbo-1

The brevity of this statement makes its literal reading ridiculous ... of the 19/20 z>5.7 quasars mentioned in the Strauss video, no comments about "evolution with redshift" were made. Presumably turbo-1 meant that AGNs show no evolution with redshift, over the range ~0.1 < z ~6.5. If so, to ask a single paper to explain this reported result AND the observed metallicity of ~20 z>5.7 quasars is a bit extreme (unless it were a review paper).

The offhandedness of your remark make its literal reading ridiculous Nereid. I expect better of you. Strauss made this comment rather forcefully in the presentation, and the 2002 paper that matt.o dug up reinforces it. Strauss points out that because MgII and FeII are formed and distributed by different kinds of SN events, some redshift-dependent evolution in the relative metallicities had been expect. None was found, nor was a redshift-dependent evolution in total metallicity found. This is a major point. It would be difficult to miss these points in Strauss' presentation.

What one finds in the literature today are observations like those done by SDSS and others, with error bars, etc. (good science) and more speculative stuff. The more speculative papers say things like "z~6.5 quasars are massive and so mass must accrete faster than we have previously considered" and "z~6.5 quasars are highly metallized, so metals must be formed in some fashion that we have not previously considered". These are statements of faith in BB cosmology, not science, because they rely on invocation of as-yet unknown processes by which these extreme objects might have been able to form. Astronomy is an observational science, and observing objects at the limits of detectability it a tricky business. Re-building cosmology based on a small sample of single-band detections at z~5.7 should be viewed as an exercise in speculation, IMO.

I hope to have a bit more uninterrupted time to devote to this thread. More later.

 

[Nereid]

I think it should be Pentericci et al. 2002, AJ, 123, 2151. See the http://adsabs.harvard.edu/abs/2002AJ...123.2151P"

Thanks matt.o.

That's an interesting paper, for sure ... but it's not what Strauss mentioned in the video ...

Here, again, is what I wrote earlier (https://www.physicsforums.com/showpost.php?p=2020453&postcount=54"):

It starts at ~20:15 minutes, and slide 36:

"A similar [game?] that Pentericci et al. have done using the VLT, they've taken the near-IR spectra, now not of ... this is a sample that you can see is not exclusively of the very high redshifts, going from redshift 4.7 to 5.8, and in this case the game is to take spectra of the rest-frame around 2800Å, so this emission line of magnesium and also iron, and there's no obvious difference in the relative strengths, or for that matter the absolute strengths, of iron and magnesium relative to lower redshift. Magnesium and iron are generated by different types of supernovae and one might imagine that one finds differences as one starts probing back to close to the big bang. No such differences have been found yet."

Slide 36, which is also what Strauss is using in the video, has spectra of the following:

• SDSS 1433+0227 z=4.715
• SDSS 1341+0141 z=4.691
• SDSS 1204-0021 z=5.088
• SDSS 0836+0054 z=5.818

The features in the spectra are not labelled.

Pentericci et al. 2002, AJ, 123, 2151 report observations of SDSS J1030+0524 (z=6.28) and SDSS 1306+0356 (z=5.99). This paper reports Lyα, NV, CIV, and HeII (not detected); there is no mention of MgII or FeII.

 

[Nereid]

The offhandedness of your remark make its literal reading ridiculous Nereid. I expect better of you. Strauss made this comment rather forcefully in the presentation, and the 2002 paper that matt.o dug up reinforces it. Strauss points out that because MgII and FeII are formed and distributed by different kinds of SN events, some redshift-dependent evolution in the relative metallicities had been expect. None was found, nor was a redshift-dependent evolution in total metallicity found. This is a major point. It would be difficult to miss these points in Strauss' presentation.

Did you read Pentericci et al. 2002, AJ, 123, 2151?

Did you read my transcript of the Strauss video?

What one finds in the literature today are observations like those done by SDSS and others, with error bars, etc. (good science) and more speculative stuff. The more speculative papers say things like "z~6.5 quasars are massive and so mass must accrete faster than we have previously considered" and "z~6.5 quasars are highly metallized, so metals must be formed in some fashion that we have not previously considered".

Sadly, I have no more time to track down the relevant papers, so I'll simply note that your record of accuracy in this regard is less than stellar, turbo-1, and I would urge any reader interested in the current state of research to go read the relevant papers for themselves*.

These are statements of faith in BB cosmology, not science, because they rely on invocation of as-yet unknown processes by which these extreme objects might have been able to form.

You keep saying this, and I^ keep saying it is the very essence of good science.

Clearly, there is a stark disagreement.

Myself, I think the disagreement likely rests on a very big difference in perceptions of the nature of science, and the extent to which modern astrophysics and cosmology are sciences.

To get these two perceptions clearly on the table, and discussed, would likely be best done by continuing the thread https://www.physicsforums.com/showthread.php?t=170753"; would you care to continue there?

Astronomy is an observational science, and observing objects at the limits of detectability it a tricky business. Re-building cosmology based on a small sample of single-band detections at z~5.7 should be viewed as an exercise in speculation, IMO.

Not sure what you're saying here, turbo-1, would you please clarify?

Specifically, are you saying that observations of "a small sample of single-band detections at z~5.7" should not form any part of evidence for alternative cosmological theories (e.g. those positing a "spatially and temporally infinite universe")?

I hope to have a bit more uninterrupted time to devote to this thread. More later.

Sadly, I have no more such time.


* it's a big task; there are hundreds of them
^ and some others too

 

[Sundance]

Re: Laura Pentricci papers

I was in the middle of reading these papers when I saw your comments.

L.Pentericci
http://arxiv.org/find/all/1/all:+Pentericci/0/1/0/all/0/1

Maybe reading some of these papers may add light to the discussion.

 

[Nereid]

Nereid, your strength seems to be cross-examination, judging from numerous posts in this most illuminating thread. Since cosmology is a subject that in the absence of experimentation depends on ratiocination and analysis of circumstantial evidence, your stance as council for the defence of the current consensus is entirely appropriate. I, for one, certainly enjoy it.

[...]

Glad you are enjoying it, oldman.

Of course, it's not only cosmology*; that pretty much describes all of astrophysics too (and geology and paleontology and ...).

One thing I find curious, and frustrating, is the extent to which pseudo-science, and even anti-science, shows up here in PF, despite https://www.physicsforums.com/showthread.php?t=5374"^; another is just how poorly understood the actual work of cosmologists, astrophysicists, and astronomers is - look at the myriad of things PF posters seem to mean when they use the word "observation" for example, blithely unaware (for the most part) of just how steeped in physics theories these observations actually are.

* "a subject that in the absence of experimentation depends on ratiocination and analysis of circumstantial evidence"
^ "Poorly formulated personal theories, unfounded challenges of mainstream science, and overt crackpottery will not be tolerated anywhere on the site". While there are some examples of misunderstandings of cosmology, as a science, and perhaps one or two examples of pseudo-science, in this thread, it is not an example of anti-science.

 

[Nereid]

Re: Laura Pentricci papers

I was in the middle of reading these papers when I saw your comments.

L.Pentericci
http://arxiv.org/find/all/1/all:+Pentericci/0/1/0/all/0/1

Maybe reading some of these papers may add light to the discussion.

That was one of the first places I looked, Sundance, for "Pentericci et al. 2005 VLT near-IR spectra".

She has certainly (co-)written many interesting papers, but the one Strauss mentions in his video (and accompanying Supporting Material) is clearly not in the list in your link.

 

[Sundance]

What is the issue?

What is the point of discussion?

 

[turbo]

Myself, I think the disagreement likely rests on a very big difference in perceptions of the nature of science, and the extent to which modern astrophysics and cosmology are sciences.

To get these two perceptions clearly on the table, and discussed, would likely be best done by continuing the thread https://www.physicsforums.com/showthread.php?t=170753"; would you care to continue there?

No. Lieu and Disney make their cases in generalities, and I am not about to defend their opinions/points of view. I have made some very specific statements about Strauss' overview of the SDSS observations that pose severe constraints on our current models of metallicity and mass-formation, only to see them either nay-sayed or ignored or "addressed" with mainstream citations that don't address the problems appropriately.

Specifically, are you saying that observations of "a small sample of single-band detections at z~5.7" should not form any part of evidence for alternative cosmological theories (e.g. those positing a "spatially and temporally infinite universe")?

You know that I am NOT saying that - you are reading into my intentions and thoughts. Such observation must be taken into account, but the small sample size and the artificial constraint of z~6.5 (which corresponds to the limits of detection of the SDSS equipment through a single filter) makes the risk of errors due to selection effects a very real problem.

I have shown that our current view of stellar neucleosynthesis constrains the rate at which FeII can be formed, as it is the last and heaviest metal that can be formed through fusion. Sadly, no engagement on this count.
https://www.physicsforums.com/showpost.php?p=2019946&postcount=42

I have shown you that the formation of even z~6 quasar masses poses some severe problems in current cosmology. This was from a mainstream paper that you cited.
https://www.physicsforums.com/showpost.php?p=2019946&postcount=42

Sadly, I have no more time to track down the relevant papers, so I'll simply note that your record of accuracy in this regard is less than stellar, turbo-1, and I would urge any reader interested in the current state of research to go read the relevant papers for themselves*.

I encourage any interested readers to listen to the Strauss presentation in the OP. When (s)he gets to the part when he explains that there is no red-shift dependent evolution apparent in either absolute nor relative concentrations of MgII or FeII in these quasars, refer to Post 40, in which Neried denies that Strauss ever made such a statement. In fact, Strauss went on to say that there was no red-shift dependent evolution apparent in any of the metrics by which SDSS evaluated these quasars. Cherry-picking indeed. Color added for emphasis and comparison with my alleged "less than stellar record of accuracy."

and show no evolution with redshift - turbo-1

The brevity of this statement makes its literal reading ridiculous ... of the 19/20 z>5.7 quasars mentioned in the Strauss video, no comments about "evolution with redshift" were made. Presumably turbo-1 meant that AGNs show no evolution with redshift, over the range ~0.1 < z ~6.5. If so, to ask a single paper to explain this reported result AND the observed metallicity of ~20 z>5.7 quasars is a bit extreme (unless it were a review paper).

 

[turbo]

What is the issue?

What is the point of discussion?

Read the OP, Sundance and view Michael Strauss' presentation to the astronomers at the Space Telescope Science Institute.

 

[Sundance]

Re First post by Turbo

Scroll down to Nov 2, 2005 and watch Michael Strauss' presentation to the Space Telescope Science Institute. Strauss is the scientific spokesperson for the Sloan Digital Sky Survey, and has co-authored many ground-breaking papers. There are several points that he makes about quasars in this presentation that should give any loyal BB-adherent pause.

1) SDSS has observed quasars out to z~6.5. Because luminosity falls off as a function of the square of the distance (absent absorption), if quasars are at the distances implied by their redshifts, these distant quasars would have be be powered by black holes of several billion Solar masses, cannibalizing host galaxies of over a trillion Solar masses. Since z~6.5 corresponds to a time a few hundred million years after the BB, how did these monsters have time to form?

2) These high-z quasars have solar or super-solar metallicities. Our Sun is presumably the product of generations of supernovae, so how did these massive bodies get so metal-enriched so early?

3) Because elements are formed in stars through different processes, cosmologists expected to see some evolution in the metallicities of quasars with redshift. SDSS found none, even out to z~6.5, either in absolute or relative metallicity.

4) Cosmologists expected that higher-redshift quasars would stand a much higher chance of being lensed because of the very long distances and the increased chance of intervening massive objects on our line-of-sight to them. None of the z=5.7-6.5 quasars in the SDSS survey are lensed.

Re 1)

Some of these monster cluster,cluster of galaxies require over 50 billion yrs to form. That is the reality, now the dating process that has been used only dates from a specific phase and does not take into consideration transient phases, so we have dating of about 13 to 14 billion years even though some star are dated over 15 billion years. Not to mention 18 Billion Sun mass BH that has a life span of over 100 Gyrs.

Re 2) The phase changes that Stars go through alter the metallicity by photodisintegration in the early stages of supernova that enable to break down of eg Fe to He to H to Neutrons and through a property of magnetic entanglement are compacted and are collected by the core to sometimes form a Neutron star. The matter avialble would determine the extent of the Neutron star or composite or even the next transient phase of a formation of a black hole form that has entrapping horizons.
Metallicity in stars is a general explanation and you can google for the information.

Re 2) Quasars near and far have been found to have the same properties. There are varies forms of quasars large and small. The extreme large ones contain a monster black hole that forms main jets that can eject matter for millions of light years affecting not only the form of the lacal galaxies but also the form of distant galaxies. Its power can form dwarf galaxies that in time merge and form larger galaxies. Because they are located in the centre of clusters of galaxies we need to search far in order to find them. Think about it, where is the centre of the nearest cluster of cluster of galaxies?
The reality of it is that we can observe the workings of the nearest without the complicated observation of the far, where data can be in error from intrinisc properties. Our tools at the present time are limited.

Re 3) Monster Objects deep field give us a better understanding of lensing because we can see the overall affect. Within the next few years we hope to get a better understanding through better science.

The issue that comes to mind is that many scientists assume that the BBT is correct than proceed to fit the data to the model. Lately scientists have been applying science to the data and their comments are closer to reality in so to speak. One of the problems with the science comminity is that the main projects are directed to the BBT that is paid for by politics and churches. If you have alternative theories your on your own and best of luck.

The general theme is that galaxies near and far have similar properties and in many cases we are discovering new forms and new properties and why not, we are still discovering new species in rainforsts and in the depths of the oceans.

Well that's my opinion.

 

[Suede]

I like turbo.

Here is a guy that looks a data and takes it for what it is.

The process of fitting models to observations are what led to the creation of Ptolemy's epicycles.

Science MUST be backed by falsifiable experiments or its no better than myth.

 

[Chronos]

Taking data at face value is precisely what Ptolemy did. And in all fairness to Ptolemy, his 'epicycles' fit observational data remarkably well for many years. But, it was not the best [simplest] explanation in the long run. No model is immune to the relentless march of science. Even GR will eventually yield to scientific progress.

 

[Suede]

Even GR will eventually yield to scientific progress.

The sooner the better IMHO.

Speaking of falsifiable, anyone have a status on the LIGO's findings?

How about the CDMS project?

Gravity Probe B?

hmmm...


As for Ptolemy matching observational data, the end result is expected. When you match models to observation without conducting fasifiable experiments, it ceases to be science and instead becomes dogma.

 

[Nereid]

Evolution of metallicity in galaxies ...

Here's an interesting, recent paper* that has considerable relevance to some of the broader issues turbo-1 raises in this thread:

http://arxiv.org/abs/0806.2410" :

We present initial results of an ESO-VLT large programme (AMAZE) aimed at determining the evolution of the mass-metallicity relation at z>3 by means of deep near-IR spectroscopy. Gas metallicities are measured, for an initial sample of nine star forming galaxies at z~3.5, by means of optical nebular lines redshifted into the near-IR. Stellar masses are accurately determined by using Spitzer-IRAC data, which sample the rest-frame near-IR stellar light in these distant galaxies. When compared with previous surveys, the mass-metallicity relation inferred at z~3.5 shows an evolution much stronger than observed at lower redshifts. The evolution is prominent even in massive galaxies, indicating that z~3 is an epoch of major action in terms of star formation and metal enrichment also for massive systems. There are also indications that the metallicity evolution of low mass galaxies is stronger relative to high mass systems, an effect which can be considered the chemical version of the galaxy downsizing. The mass-metallicity relation observed at z~3.5 is difficult to reconcile with the predictions of some hierarchical evolutionary models. Such discrepancies suggest that at z>3 galaxies are assembled mostly with relatively un-evolved sub-units, i.e. small galaxies with low star formation efficiency. The bulk of the star formation and metallicity evolution probably occurs once small galaxies are already assembled into bigger systems.

At any given epoch, AGNs are rare objects, compared with galaxies.

Even today, I think it's true to say that AGNs are quite poorly understood, compared with galaxies^.

How galaxies evolve - in terms of their gas content, morphology, rate of star formation, etc, etc, etc - is a relatively recent topic in astrophysics.

Even more recent is high quality observations of high-z galaxies, which can be used to study various aspects of galaxy evolution (among other things).

Thus it's not unreasonable to expect that detailed understanding of how AGNs evolve will likely trail similar understanding of how galaxies evolve, though AGN evolution will certainly be informed by results obtained from studying galaxy evolution.

In any case, research into the formation of both AGNs and galaxies is highly constrained today by an almost complete lack of relevant observations ... about all we know is that it took place in the Dark Ages, between the surface of last scattering and the epoch of re-ionisation.

The introduction section of the Maiolino et al. paper is worth reading carefully; one gets a real sense of both excitement and of how little is yet firmly established.

The second two paras of the introduction are well worth quoting, as they illustrates well just how much, and how little, is known (plus how active a field of research this is):

Various physical processes may be responsible for the mass-metallicity relation. One possibility is that outflows, generated by starburst winds, eject metal-enriched gas into the IGM preferentially out of low-mass galaxies (due to the shallow gravitational potential well),making their enrichment less effective than in massive systems (e.g. Tremonti et al., 2004; De Lucia et al., 2004; Finlator & Dav´e, 2008). An alternative scenario is that low mass systems are still at an early evolutionary stage and have still to convert most of their gas into stars, hence they are poorly metal-enriched relative massive galaxies (which are instead already evolved). This is the so-called “galaxy downsizing” scenario, supported by various observational evidences (e.g. Juneau et al., 2005; Feulner et al., 2005; Franceschini et al., 2006; Asari et al., 2007; Perez-Gonzalez et al., 2007), where massive galaxies formed most of their stars rapidly and at high redshift, while low mass systems are characterized by a slower evolution, which extends to low redshift. Finally K¨oppen et al. (2007) ascribes the mass-metallicity relation to variations of the IMF high-mass cutoff in different star forming environments.

The relative role of these processes in shaping the mass-metallicity relation is debated. It is likely that each of them contributes at least to some extent, since observational evidences have been found for all of them. Each of these factors (outflows/feedback, downsizing, IMF) has profound implications on the evolution of galaxies. Therefore, it is clear that the mass-metallicity relation contains a wealth of information useful to constrain models of galaxy formation and evolution. Indeed, any model of galaxy evolution is now required to match the mass–metallicity relation observed locally (e.g. Kobayashi et al., 2007; Brooks et al., 2007; de Rossi et al., 2007; Dav´e & Oppenheimer, 2007; Dalcanton, 2007; De Lucia et al., 2004; Tissera et al., 2005; Bouch´e et al., 2006, 2007; K¨oppen et al., 2007; Cid Fernandes et al., 2007; Finlator & Dav´e, 2008; Tassis et al., 2008). However, different models predict different evolutionary patterns of the mass-metallicity relation as a function of redshift, and observational data are required to test and discriminate among them.

We surely live in (astrophysical) exciting times!

* actually a preprint, though is apparently "in press" (A&A)
^ with the exception of extreme dwarf galaxies

 

[matt.o]

Hot off the press today on astro-ph (accepted for publication in A&A):

http://arxiv.org/abs/0901.0974"

Particularly pertinent is the comparison of model to observation which demonstrates the bias present in observing these high redshift objects (see Fig. 3). Also of interest is the carbon abundance.

The metallicity of the most distant quasars
Authors: Y. Juarez, R. Maiolino, R. Mujica, M. Pedani, S. Marinoni, T. Nagao, A. Marconi, E. Oliva
(Submitted on 8 Jan 2009)

Abstract: We investigate the metallicity of the broad line region (BLR) of a sample of 30 quasars in the redshift range 4<z<6.4, by using near-IR and optical spectra. We focus on the ratio of the broad lines (SiIV1397+OIV]1402)/CIV1549, which is a good metallicity tracer of the BLR. We find that the metallicity of the BLR is very high even in QSOs at z~6. The inferred metallicity of the BLR gas is so high (several times solar) that metal ejection or mixing with lower metallicity gas in the host galaxy is required to match the metallicities observed in local massive galaxies. On average, the observed metallicity changes neither among quasars in the observed redshift range 4<z<6.4, nor when compared with quasars at lower redshifts. We show that the apparent lack of metallicity evolution is a likely consequence of both the black hole-galaxy co-evolution and of selection effects. The data also suggest a lack of evolution in the carbon abundance, even among z>6 quasars. The latter result is puzzling, since the minimum enrichment timescale of carbon is about 1 Gyr, i.e. longer than the age of the universe at z~6.

 

[marcus]

http://arxiv.org/abs/0901.0974"
...
The data also suggest a lack of evolution in the carbon abundance, even among z>6 quasars. The latter result is puzzling, since the minimum enrichment timescale of carbon is about 1 Gyr, i.e. longer than the age of the universe at z~6.

Matt,
that is intriguing. Suppose it's true. Suppose these things are already rich in carbon at z=6.

Why does the minimum enrichment timescale have to be 1 Gyr?
Doesn't that just mean that there were some huge early stars that got in there fast and cooked up a lot of carbon real quick?

I guess what I'm asking about is the amount of wiggle in the accepted early universe carbon enrichment story.

 

[Chronos]

I think it means back to the drawing board for nucleosynthesis. Metallization may have occurred much more rapidly in the early universe than we can currently explain - at least in the case of extremely bright objects. I don't perceive that as a threat to any cosmological model at present.

 

[matt.o]

Hi Marcus,

Matt,
that is intriguing. Suppose it's true. Suppose these things are already rich in carbon at z=6.

Why does the minimum enrichment timescale have to be 1 Gyr?
Doesn't that just mean that there were some huge early stars that got in there fast and cooked up a lot of carbon real quick?

I guess what I'm asking about is the amount of wiggle in the accepted early universe carbon enrichment story.

Well, apparently the carbon enrichment is due primarily to AGB (asymptotic giant branch) stars and planetary nebulae which evolve on long timescales. I think AGB stars are the end results of medium mass stars, thus take some time to evolve to a stage where they are expelling carbon. I'm not sure where they got the 1Gyr value from (I'd have to did deeper into the referenced papers), but I do know AGB stars and their feedback winds are hard to model in stellar population models (at least according to Bruzual and Charlot 2003) and thus there could be some wiggle room there.

 

[turbo]

Here is a recent paper. (which matt.o has referenced)

http://arxiv.org/abs/0901.0974

The current model is that mass accretes (through whatever means - there are lots of models) the quasar fires off, and then radiates strongly enough to sweep away local gas/dust so the EM radiation from the accreting BH/quasar is visible to us. This is a wonderful model at low redshifts - not so much at high redshifts, because we still have to manage to figure out how very heavy elements might have already formed and have been incorporated into the quasars, so that we can observe them at high redshift.

If we want to believe that elements heavier than those that might have been created in the BB evolve through stellar synthesis, then perhaps there is reason to explore our options. We can't reasonably expect the (accretion/stellar synthesis/nova/accretion) cycle to explain what we see.

 

[Sundance]

The form of the galaxy or cluster of galaxies is directly related to the mass and activity of the so called black hole. Black holes vary in size and activty during the evolution phases spiral to elliptical to spiral and so on with various forms in between.

Tubo the link you provided, is great reading.

The metallicity of the most distant quasars
Authors: Y. Juarez, R. Maiolino, R. Mujica, M. Pedani, S. Marinoni, T. Nagao, A. Marconi, E. Oliva
(Submitted on 8 Jan 2009)

Abstract: We investigate the metallicity of the broad line region (BLR) of a sample of 30 quasars in the redshift range 4<z<6.4, by using near-IR and optical spectra. We focus on the ratio of the broad lines (SiIV1397+OIV]1402)/CIV1549, which is a good metallicity tracer of the BLR. We find that the metallicity of the BLR is very high even in QSOs at z~6. The inferred metallicity of the BLR gas is so high (several times solar) that metal ejection or mixing with lower metallicity gas in the host galaxy is required to match the metallicities observed in local massive galaxies. On average, the observed metallicity changes neither among quasars in the observed redshift range 4<z<6.4, nor when compared with quasars at lower redshifts. We show that the apparent lack of metallicity evolution is a likely consequence of both the black hole-galaxy co-evolution and of selection effects. The data also suggest a lack of evolution in the carbon abundance, even among z>6 quasars. The latter result is puzzling, since the minimum enrichment timescale of carbon is about 1 Gyr, i.e. longer than the age of the universe at z~6.

What does this say about the age of the universe?

 

[matt.o]

Is there an echo in here?

 

[Suede]

http://www.haltonarp.com/articles/origins_of_quasars_and_galaxy_clusters":

Quasars are proto-galaxies ejected from parent galaxies.

Redshift of quasars is a function of galactic aging.

Younger quasars have high redshifts, as they mature after ejection, they become lower redshift.


hmmm... seems to fit with the data at a lot of levels no?

I'm sure we could poke holes in it, but its certainly interesting to note the problems in the data such a theory would solve.

 

[Sundance]

Quasars is the term used to explain an object that looks star like.


Quasars of various sizes and origin can be found.

The extreme case is quasars that are found in the centre of cluster of galaxies, having extreme mass, a monster jet, large surrounding halo etc.

The other extreme is where a body is ejected from a black hole such as a microquasar, a star looking body.

 

[Nereid]

Here is a recent paper. (which matt.o has referenced)

http://arxiv.org/abs/0901.0974

The current model is that mass accretes (through whatever means - there are lots of models) the quasar fires off, and then radiates strongly enough to sweep away local gas/dust so the EM radiation from the accreting BH/quasar is visible to us. This is a wonderful model at low redshifts - not so much at high redshifts, because we still have to manage to figure out how very heavy elements might have already formed and have been incorporated into the quasars, so that we can observe them at high redshift.

If we want to believe that elements heavier than those that might have been created in the BB evolve through stellar synthesis, then perhaps there is reason to explore our options. We can't reasonably expect the (accretion/stellar synthesis/nova/accretion) cycle to explain what we see.

The Juarez et al. preprint paints, in the Discussion section, a plausible explanation for why the inferred BLR metallicities of SDSS-selected quasars are roughly constant* (section 4.1, first para):

The apparent lack of evolution observed in Figs. 1–2 should not be interpreted as a lack of evolution of the BLR metallicity in individual AGNs. Indeed, Fig. 1 shows the average metallicity of the BLR in quasars that are accreting at the given redshift, but does not trace the evolutionary path of individual quasars. The apparent lack of evolution in the BLR metallicity observed in Fig. 1 likely results from a combination of the BH-galaxy coevolution and selection effects. Indeed, to cross the detection threshold of the SDSS magnitude-limited survey, high-redshift quasars must have high luminosities, hence (even if accreting at the Eddington limit) high black hole masses. Most models predict that high black holemasses must have been accompanied by the formation of a massive host galaxy (e.g. Granato et al., 2004; Di Matteo et al., 2005; Hopkins et al., 2008; Li et al., 2007), which would result into the local MBH − Mspheroid relationship. Therefore, by the time a quasar at any redshift is detectable in a magnitude-limited survey, its host galaxy must have evolved significantly and enriched its ISMsignificantly. The quasar feedback is another evolutionary effect that may yield to observational biases resulting in an apparent lack of metallicity evolution. Indeed, according to many models, during the early phases, when the host galaxy is still metal poor, the accreting black hole is embedded within the dusty ISM, and therefore difficult to detect in optical surveys. Only during the late evolutionary phases, when the galaxy is already metal rich, the quasar develops winds powerful enough to expel large quantities of gas and dust, so that the quasar becomes visible to optical observations.

The next para presents a tentative, quantitative look at this, and section 4.1 concludes:

"Summarizing, the co-evolution of black holes and galaxies, combined with observational selection effects (mostly in optical surveys), naturally explains the finding that unobscured quasars of a given luminosity appear to have on average the same metallicity at any redshift."

* do not show significant change as a function of z

 

[Nereid]

Matt,
that is intriguing. Suppose it's true. Suppose these things are already rich in carbon at z=6.

Why does the minimum enrichment timescale have to be 1 Gyr?
Doesn't that just mean that there were some huge early stars that got in there fast and cooked up a lot of carbon real quick?

I guess what I'm asking about is the amount of wiggle in the accepted early universe carbon enrichment story.

(bold added)

Juarez et al. make it clear that 'the carbon problem' needs more work before it could be said to be well-established.

The part where they discuss it - section 4.3 - is both in the Discussion section and brief (just one para long), and concludes ('this issue' is the apparent large carbon abundance in the BLR):

We note that this issue is independent of the size and mass of the BLR, making it just a pure timescale problem. Tackling this issue requires a more accurate determination of the carbon abundance, which may come from future high spectral resolution optical/near-IR observations or from future submm observations of far-IR fine structure lines (Maiolino, 2008).

In addition to the observational aspects, the relationship of the abundance of carbon in the BLR to that in the gas and stars of the host galaxy will need to be addressed, both observationally and theoretically (as matt.o has already noted). And the theoretical modelling will need to address some difficult questions about the behaviour of systems that have no counterparts in the local universe (as Chronos has already noted).

Its all fascinating stuff, and you can easily understand why it's a hot research topic.

 

[Nereid]

http://www.haltonarp.com/articles/origins_of_quasars_and_galaxy_clusters":

Quasars are proto-galaxies ejected from parent galaxies.

Redshift of quasars is a function of galactic aging.

Younger quasars have high redshifts, as they mature after ejection, they become lower redshift.


hmmm... seems to fit with the data at a lot of levels no?

I'm sure we could poke holes in it, but its certainly interesting to note the problems in the data such a theory would solve.

Arp's ideas on quasars can be left to enjoy their well-deserved, and well-earned, retirement, in the pages of the book Ideas In Astronomy That Didn't Pan Out.

In its simplest, highly summarised, form: quasars are AGNs, just as Seyfert 1s, blazars, type 2 quasars, etc, etc, etc are. They are a homogeneous class of astronomical object. Their observed redshifts are reliable indicators of their distance (in time and space), not least because dozens of (strongly) lensed quasars have been found.

Of the order of half the Strauss video, and accompanying powerpoint slides, that turbo-1 introduces in this thread, is taken up with presentation of (then) recent observational results that strengthen "The canonical modern picture of active galaxy structure" (to quote the title of slide 70). In addition, in the video Strauss talks about the Gunn-Peterson trough and how the signature of the end of the Dark Ages can be seen in the spectra of high-z quasars (just as predicted over 35 years ago, from standard cosmological models).

Oh, and as a side note, Arp's ideas on quasars must surely count as spectacular failures when subject to the Suede 'laboratory proof' test!

 

[Jonathan Scott]

From what I've been reading in the last few days, I've been getting the impression that the arguments often work as follows - I do hope this isn't really the case!

If a quasar appears to be in the middle of a galaxy, fuzzy blob or whatever, compare the redshift of the quasar and the galaxy:

1. If the quasar's redshift is higher, it must be behind the galaxy, "proving" that it is further away and hence that its redshift is cosmological.

2. If the quasar's redshift is close to that of the galaxy, it is obviously within the galaxy, "proving" that quasar redshifts are not intrinsic.

In reality, I'd hope that there would be lots of other factors taken into account, like details of spectral lines, whether the quasar appeared to be at the centre of the galaxy and so on. However, I can't help being a little suspicious.

 

[Nereid]

From what I've been reading in the last few days, I've been getting the impression that the arguments often work as follows - I do hope this isn't really the case!

If a quasar appears to be in the middle of a galaxy, fuzzy blob or whatever, compare the redshift of the quasar and the galaxy:

1. If the quasar's redshift is higher, it must be behind the galaxy, "proving" that it is further away and hence that its redshift is cosmological.

2. If the quasar's redshift is close to that of the galaxy, it is obviously within the galaxy, "proving" that quasar redshifts are not intrinsic.

In reality, I'd hope that there would be lots of other factors taken into account, like details of spectral lines, whether the quasar appeared to be at the centre of the galaxy and so on. However, I can't help being a little suspicious.

Hi JS,

I don't know how you formed this impression!

Perhaps you could explain how, in some detail?

FWIW, your description bears only a coincidental resemblance to what contemporary standard procedure is. And as an example, let's see what Juarez et al. say, in the preprint cited in several posts in this thread, about how they measured the redshifts (etc); here is section 2 (Observations) in its entirety (some formatting and characters may be lost):

We observed a sample of 30 high-redshift quasars (4.0 < z < 6.4) from the SDSS by means of near-IR and optical spectra covering at least the UV rest-frame emission lines SiIVλ1397+OIV]λ1402 and CIVλ1549, but in most cases the spectra extend to λrest ∼ 3000 − 4000Å. The original goal of most of the observations was to constrain the dust extinction in high-z QSOs. A more detailed description of the data and the results on the dust extinction will be given in Gallerani et al. (in prep.). Here we only focus on a byproduct, namely the evolution of the BLR metallicity based on the (SiIV+OIV)/CIV ratio.

Observations were obtained both with the Italian Telescopio Nazionale Galileo (TNG) in Spain and with the Very Large Telescope (VLT)-ESO in Chile. Observations were performed in several observing runs from 2003 to 2005. The observations at the TNG were obtained with the Near Infrared Camera Spectrograph (NICS) mostly with the Amici prism to obtain spectra in the range 0.9-2.3 μm at R∼75. This low-resolution mode is excellent for investigating the QSO continuum shape, but also for detecting broad emission lines. Some QSOs were observed again with the IJ grism to obtain 0.9-1.45 μm spectra at R∼500. Typical integration times ranged from ∼20 minutes to ∼3 hours. The observing strategy and data reduction are similar to those discussed in Maiolino et al. (2004).

The spectroscopic observations at ESO-VLT were done with the FORS2, along with the grismGRIS150I, to observe the range 6000-11000 Å at R∼300. These observations are mostly used to cover the short-wavelength part of some of the quasar spectra not properly sampled by the near-IR observations, but we also specifically observed a few quasars with no near-IR data with the specific aim of measuring the (SiIV+OIV)/CIV ratio. The total exposure times range from 30 to 60 minutes. For some of the z < 5 quasars observed with NICS, for which no FORS2 observations were available, we combine our near-IR spectra with optical data taken from Anderson et al. (2001).

Perhaps you are unfamiliar with the term "BLR"? It stands for "broad line region" and is not resolved in images of any quasar (that I know of), nor in the UV/optical/nearIR waveband images of any AGN either* (and, for completeness, if you can't resolve/separate something in an image, you certainly can't take a separate spectrum of it!).

Maybe a read of Maiolino et al. (2004) would help you?

* IIRC; if anyone knows of any reported observations of an AGN's resolved BLR ...

 

[Suede]

Oh, and as a side note, Arp's ideas on quasars must surely count as spectacular failures when subject to the Suede 'laboratory proof' test!

Plasmoid ejection from current pinches is a well known laboratory proven phenomina.

btw,

The Discovery of a High Redshift X-ray Emitting QSO Very Close to the Nucleus of NGC 7319
Pasquale Galianni, E.M. Burbidge, H. Arp, V. Junkkarinen, G. Burbidge, Stefano Zibetti
Astrophys.J. 620 (2005) 88-94
http://arxiv.org/abs/astro-ph/0409215

A strong X-ray source only 8" from the nucleus of the Sy2 galaxy NGC 7319 in Stephan's Quintet has been discovered by Chandra. We have identified the optical counterpart and show it is a QSO with $z_e = 2.114$. It is also a ULX with $L_x = 1.5 x 10^{40} erg sec^{-1}$. From the optical spectra of the QSO and interstellar gas in the galaxy (z = .022) we show that it is very likely that the QSO and the gas are interacting.




Probably just another freak coincidence though.

like this, NGC 7319:

or this, NGC 4319:

http://www.answersingenesis.org/images/quasar.jpg

or this, NGC 7603:

 

[Nereid]

Oh, and as a side note, Arp's ideas on quasars must surely count as spectacular failures when subject to the Suede 'laboratory proof' test!

Plasmoid ejection from current pinches is a well known laboratory proven phenomina.

In which the following have been 'proven'*:
- the creation of mass?
- atoms, nuclei, and electrons whose mass decreases with time?
- violation of conservation of momentum, energy, and angular momentum?
- violation of at least two of the laws of thermodynamics?

Not to mention that no lab has ever performed a controlled experiment on an object of mass 10^6 (or more) sols, in a volume of 1 kpc^3 (or more).

Suede, this is beyond absurd.

btw,

The Discovery of a High Redshift X-ray Emitting QSO Very Close to the Nucleus of NGC 7319
Pasquale Galianni, E.M. Burbidge, H. Arp, V. Junkkarinen, G. Burbidge, Stefano Zibetti
Astrophys.J. 620 (2005) 88-94
http://arxiv.org/abs/astro-ph/0409215

A strong X-ray source only 8" from the nucleus of the Sy2 galaxy NGC 7319 in Stephan's Quintet has been discovered by Chandra. We have identified the optical counterpart and show it is a QSO with $z_e = 2.114$. It is also a ULX with $L_x = 1.5 x 10^{40} erg sec^{-1}$. From the optical spectra of the QSO and interstellar gas in the galaxy (z = .022) we show that it is very likely that the QSO and the gas are interacting.

Yep, that's a well-known, and much discussed paper.

As with many (most?) of these Arp (et al.) papers, the 'very likely interacting' interpretation rests almost entirely on perceived alignments of features in images ... and where it doesn't, it requires a) an 'intrinsic redshift' that has no counterpart in standard physics**, and b) the 'interacting' material to have no intermediate redshift (which is inconsistent with the Arp idea you posted earlier). Further, with the widespread and easy availability of codes to model the interaction between a compact high-mass object and a galaxy, it's curious that no Arp et al. paper has been published showing the plausibility of the purported 'interaction' via simulation (with or without variable mass, etc).

Applying Occam's razor, and keeping in mind the huge amount of solid research showing that AGNs are a homogeneous class of object, we can conclude that this quasar is being viewed through NGC 7319.

* these are all core aspects of Arp's idea
** no one has published a paper showing that the Wolf effect, to take just one example, is consistent with all well-established features in the relevant spectra, for example

 

[Suede]

I'm not going to argue Arp's theory with you because doing so will result in me getting banned from these boards, which I'm sure would please you greatly.

Its enough to say I believe him and the theories that support his claim are scientifically credible, rely on known plasma physics, and don't postulate any hypothetical matters and energies.

btw,

http://www.skepticalinvestigations.org/controversies/images/NGC4319.jpg

 

[Sundance]

Arp has contributed great works in many fields.

Which part has been proven wrong?

It is not very scientific just saying that he has been proven wrong.


Neried quote

Suede, this is beyond absurd.


btw,

The Discovery of a High Redshift X-ray Emitting QSO Very Close to the Nucleus of NGC 7319
Pasquale Galianni, E.M. Burbidge, H. Arp, V. Junkkarinen, G. Burbidge, Stefano Zibetti
Astrophys.J. 620 (2005) 88-94
http://arxiv.org/abs/astro-ph/0409215

A strong X-ray source only 8" from the nucleus of the Sy2 galaxy NGC 7319 in Stephan's Quintet has been discovered by Chandra. We have identified the optical counterpart and show it is a QSO with $z_e = 2.114$. It is also a ULX with $L_x = 1.5 x 10^{40} erg sec^{-1}$. From the optical spectra of the QSO and interstellar gas in the galaxy (z = .022) we show that it is very likely that the QSO and the gas are interacting.

Which part is absurd?

 

[Nereid]

Arp has contributed great works in many fields.

Which part has been proven wrong?

It is not very scientific just saying that he has been proven wrong. Neried quote

Suede, this is beyond absurd.btw,

The Discovery of a High Redshift X-ray Emitting QSO Very Close to the Nucleus of NGC 7319
Pasquale Galianni, E.M. Burbidge, H. Arp, V. Junkkarinen, G. Burbidge, Stefano Zibetti
Astrophys.J. 620 (2005) 88-94
http://arxiv.org/abs/astro-ph/0409215

A strong X-ray source only 8" from the nucleus of the Sy2 galaxy NGC 7319 in Stephan's Quintet has been discovered by Chandra. We have identified the optical counterpart and show it is a QSO with $z_e = 2.114$. It is also a ULX with $L_x = 1.5 x 10^{40} erg sec^{-1}$. From the optical spectra of the QSO and interstellar gas in the galaxy (z = .022) we show that it is very likely that the QSO and the gas are interacting.

Which part is absurd?

First of all Sundance, I'd appreciate it if you quote me correctly.

Let's follow the sequence, leaving out the [ QUOTE ] tags.

In https://www.physicsforums.com/showpost.php?p=2027652&postcount=80", Suede wrote (this is the entire post, minus the link in the first line):
= = = = = = = = = = Suede, post #80 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Arp's theory:

Quasars are proto-galaxies ejected from parent galaxies.

Redshift of quasars is a function of galactic aging.

Younger quasars have high redshifts, as they mature after ejection, they become lower redshift.hmmm... seems to fit with the data at a lot of levels no?

I'm sure we could poke holes in it, but its certainly interesting to note the problems in the data such a theory would solve.
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

My post #84 followed, and quoted Suede's (#80) in full (I have left it out here):
= = = = = = = = = = Nereid, post #84 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
[Suede's post#80]

Arp's ideas on quasars can be left to enjoy their well-deserved, and well-earned, retirement, in the pages of the book Ideas In Astronomy That Didn't Pan Out.

In its simplest, highly summarised, form: quasars are AGNs, just as Seyfert 1s, blazars, type 2 quasars, etc, etc, etc are. They are a homogeneous class of astronomical object. Their observed redshifts are reliable indicators of their distance (in time and space), not least because dozens of (strongly) lensed quasars have been found.

Of the order of half the Strauss video, and accompanying powerpoint slides, that turbo-1 introduces in this thread, is taken up with presentation of (then) recent observational results that strengthen "The canonical modern picture of active galaxy structure" (to quote the title of slide 70). In addition, in the video Strauss talks about the Gunn-Peterson trough and how the signature of the end of the Dark Ages can be seen in the spectra of high-z quasars (just as predicted over 35 years ago, from standard cosmological models).

Oh, and as a side note, Arp's ideas on quasars must surely count as spectacular failures when subject to the Suede 'laboratory proof' test!
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

Suede replied, in https://www.physicsforums.com/showpost.php?p=2028094&postcount=87", and quoted just one line of my post #84. He edited this at least once, and my reply (post#88, see below) - which quoted his #87 post - did not include the parts he added subsequently. Here is post #87, up to the phrase "btw,":
= = = = = = = = = = Suede, post #87 (part only) = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
[from Nereid's post#84: Oh, and as a side note, Arp's ideas on quasars must surely count as spectacular failures when subject to the Suede 'laboratory proof' test! ]

Plasmoid ejection from current pinches is a well known laboratory proven phenomina.

btw,

[rest of Suede's post #87 omitted]
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

My https://www.physicsforums.com/showpost.php?p=2028121&postcount=88" followed. It contains two parts, and quotes Suede's post#87 in full. I shall reproduce only the first part, since it is the only part germane to my reconstruction. The embedded quote is reconstructed sequentially; the relevant footnote is moved up.
= = = = = = = = = = Nereid, post #88 (part only) = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
[from Nereid's post#84: Oh, and as a side note, Arp's ideas on quasars must surely count as spectacular failures when subject to the Suede 'laboratory proof' test! ]
[from Suede's post#87: Plasmoid ejection from current pinches is a well known laboratory proven phenomina.]

In which the following have been 'proven'*:
- the creation of mass?
- atoms, nuclei, and electrons whose mass decreases with time?
- violation of conservation of momentum, energy, and angular momentum?
- violation of at least two of the laws of thermodynamics?

Not to mention that no lab has ever performed a controlled experiment on an object of mass 10^6 (or more) sols, in a volume of 1 kpc^3 (or more).

Suede, this is beyond absurd.

* these are all core aspects of Arp's idea
[rest of Nereid's post #88 omitted]
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

I think it's pretty clear that what I meant by 'beyond absurd' is that Suede's presentation of Arp's ideas in post#80 is beyond absurd when tested using Suede's own 'laboratory proof' criteria.

At no point did I say that the 2005 Galianni et al. paper was absurd. If you have somehow read that into what I wrote, then I trust that this post corrects your misunderstanding; if it does not, please do me the courtesy of saying so, and asking for further clarification.

I do not wish to have this thread derailed by a discussion of the Arp-Narlikar variable mass hypothesis, nor by a discussion of papers reporting apparent relationships between high-z objects and low-z galaxies, etc. If a PF mentor considers either discussion to be within PF's guidelines, let's have a separate thread on each.

In any case, I shall not post any further, in this thread, on papers that present non-mainstream theories or ideas, and/or which are not part of current professional mainstream scientific discussion.

Finally, it would seem that you, Sundance, may not be aware of just how enormous and compelling the published papers on quasars are, and the vast quantity of high quality observations on which the contemporary 'unified AGN model' is built (I gave a short para summary in post#84). If you'd like to explore that more, I'd be happy to help you ... why not start a new thread on it?

 

[Suede]

All of your points have been accounted for in the theories that support Arps work.

Of course, I can't discuss them here because that will get me banned.

So it seems underhanded to attack those theories when I can't post any proof in defense of them.

You saying they lack laboratory proof does not make it so. I got a professional engineering organization with 365,000 members that says otherwise.



So what do you think about this?

http://www.skepticalinvestigations.org/controversies/images/NGC4319.jpg

 

[Suede]

Sometimes we need papers to state the obvious.


Evidence for Activity in the Spiral Galaxy NGC4319
Sulentic, J. W. Observational Evidence of Activity in Galaxies: Proceedings of the 121st Symposium of the International Astronomical Union, held in Byurakan, Armenia, U.S.S.R., June 3-7, 1986.
http://articles.adsabs.harvard.edu/full/1987IAUS..121..483S

Radio and optical evidence for activity in the spiral galaxy NGC 4319 is presented. NGC 4319 appears to be one of the first spirals to exhibit double lobe radio structure outside of the nuclear regions. The optical data show that (1) the quasar M205 is connected to the nucleus of NGC 4319 and (2) that a similarly connected region on the opposite side of the nucleus is expanding towards us with V ≡ 103km s-1. It is suggested that the unusual Hα/[N II] λ6583 ratio (≤0.3) indicates that the entire central (7 kpc diameter) disk of NGC 4319 has been shock excited by this activity.

 

[matt.o]

Sometimes we need papers to state the obvious.

http://adsabs.harvard.edu/cgi-bin/n......398..495B&db_key=AST&high=3d6e3bdf3c21424"
The near-ultraviolet spectrum of Markarian 205
Bahcall, John N.; Jannuzi, Buell T.; Schneider, Donald P.; Hartig, George F.; Jenkins, Edward B.

We report measurements of the absorption and of the emission lines between 1600 and 3200 A in the spectrum of the nearby AGN Markarian 205 (z = 0.071), which lies at a projected distance of 3 kpc (H0 = 100 km/s) from the nucleus of the nearby barred spiral galaxy, NGC 4319 (z = 0.0047). The results were obtained using high-resolution (R = 1300) observations with the Faint Object Spectrograph of the HST. A total of 15 absorption lines, 13 of which are produced by Galactic gas, and four AGN emission lines are detected. Two of the absorption lines, the Mg II resonant doublet, are produced by gas in the intervening galaxy NGC 4319. This is the first detection of absorption due to intervening gas in this famous quasar-galaxy pair.

 

[Nereid]

[snip]

So what do you think about this?

http://www.skepticalinvestigations.org/controversies/images/NGC4319.jpg

[/URL]
My first thought was "what is the source?"

My next thought was "without knowing the source, I can't be sure, but there's a high likelihood that the source has a clearly stated policy on use and (public) reproduction, if not an actual copyright."

That was followed by "hmm, PF has a clearly stated policy on this, doesn't it?"

And so I went to check.

And it is so:

Copyright Guidelines:
Copyright infringement is illegal. Physics Forums will enforce the law. Never post an article in its entirety. When posting copyrighted material, please use small sections or link to the article. When posting copyrighted material please give credit to the author in your post.

Further, another of PF's rules states, in part (bold added):

It is against our Posting Guidelines to discuss, in most of the PF forums, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion.

So my next thought was "Suede surely knows about this rule by now, so there's a very good chance that this image is taken from such a publication. In my experience, all such publications have clear guidelines on use, including, at minimum, an acknowledgment of the source. So, it's likely that Suede has goofed in not following PF's rules, or is posting material from a source other than a peer-reviewed publication."

And that lead me to my next action: to click on the REPORT button, to report the post for violation of PF's rules.

 

[Chalnoth]

From what I've been reading in the last few days, I've been getting the impression that the arguments often work as follows - I do hope this isn't really the case!

If a quasar appears to be in the middle of a galaxy, fuzzy blob or whatever, compare the redshift of the quasar and the galaxy:

1. If the quasar's redshift is higher, it must be behind the galaxy, "proving" that it is further away and hence that its redshift is cosmological.

2. If the quasar's redshift is close to that of the galaxy, it is obviously within the galaxy, "proving" that quasar redshifts are not intrinsic.

In reality, I'd hope that there would be lots of other factors taken into account, like details of spectral lines, whether the quasar appeared to be at the centre of the galaxy and so on. However, I can't help being a little suspicious.

The way that you'd actually test whether it's within or behind the galaxy would be to look for absorption spectra. If it's behind the galaxy, it will show absorption lines in its spectrum that are of the same redshift as the galaxy. If, on the other hand, it's within the galaxy, and there is dust in the galaxy between us and the quasar, then it should show absorption of the same redshift.

Typically very high-redshift quasars are so far away that their light passes through a large number of intervening gas clouds. Thus they have absorption spectra that are all over the place. Of particular interest is what is known as the Lyman-alpha forest: since most of the intervening matter is in the form of neutral hydrogen, the primary absorption is from the biggest hydrogen line: the Lyman alpha line (this is the line from the transition between the ground state and the first excited state). With these far-away quasars, the large number of intervening gas clouds at a wide range of redshifts basically kills a large portion of the spectrum of the quasar. It's basically impossible to account for the existence of the Lyman-alpha forest in Arp's model.

 

[Chalnoth]

So what do you think about this?

http://www.skepticalinvestigations.org/controversies/images/NGC4319.jpg

[/URL]
That so-called "luminous bridge" is an artifact of the way the data is gathered. Basically, if a telescope takes a picture of a point source, the optics of the telescope spread that image out into a blob. The size of the blob is called the "beam size" of the telescope, and it determines the resolution available.

The apparent connection between those two objects is clearly an effect of this beam. Obviously no competent astronomer had a hand in annotating that image.

 

[turbo]

Would you like another opinion, published in a peer-reviewed journal? A couple of "competent astronomers" wrote this one.

http://articles.adsabs.harvard.edu/full/1987ApJ...319..687S

Nay-saying and shouting down unpopular ideas are not mature behaviors, nor should they be countenanced in "scientific" circles.

 

[matt.o]

That so-called "luminous bridge" is an artifact of the way the data is gathered. Basically, if a telescope takes a picture of a point source, the optics of the telescope spread that image out into a blob. The size of the blob is called the "beam size" of the telescope, and it determines the resolution available.

The apparent connection between those two objects is clearly an effect of this beam. Obviously no competent astronomer had a hand in annotating that image.

Actually, the bridge is present in the Hubble images, too (see http://heritage.stsci.edu/2002/23/supplemental.html" ). To some extent, you are right about the PSF issue and seeing (especially given that image was taken by an amateur astronomer) enhancing this "bridge". However, I don't think the conclusions jumped to by Arp et al. hold any ground given the paper I linked above (Bahcall et al.) and the fact that if you click on the .gif movie in the link above you can see Markarian 205's host galaxy (amongst other things like the overwhelming amount of evidence in support of redshift \propto distance). You can also see the host galaxy in the second image in the link, along with a compact companion galaxy which is not resolved in the image Suede posted, therefore adding to the "bridge" luminosity.

 

[Chalnoth]

Would you like another opinion, published in a peer-reviewed journal? A couple of "competent astronomers" wrote this one.

http://articles.adsabs.harvard.edu/full/1987ApJ...319..687S

Nay-saying and shouting down unpopular ideas are not mature behaviors, nor should they be countenanced in "scientific" circles.

This is why higher-resolution images are so nice:

[click for source]

So clearly the answer is no, they weren't. Now, Halton Arp was, at one time, a competent astronomer. At some point he fell off the deep end. This is something that appears to happen to a disturbingly large number of scientists as they get older, and I have no idea why.