Quasars and Cosmology

[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 in to 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 [Broken]

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 [Broken]

 

[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 [Broken]

 

[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 [Broken]

[/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:
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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 [Broken]

[/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" [Broken]). 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.