Quasars with high redshift in nearby galaxies

[Shenstar]

http://www.sciencedaily.com/releases/2005/01/050111115201.htm

Please see this article. I've been trying to find the thread with 41 questions posted aces days ago. One of the questions was relating to high redshift objects like quasars appearing in near by galaxies. Someonevwanted a reference for such occurrences.

Yesterday I came across the abovevarticle, so I thought I'd post it here to get some possible explanations for the cosmological phenomenon.

Any ideas? Or is this false reporting?

 

[phyzguy]

Geoffrey Burbidge had this opinion (that quasar redshifts are not cosmological) for decades, and steadfastly refused to abandon it despite mountains of evidence to the contrary. Note that this article is from 2005, and that Geoffrey Burbidge has since passed away and so will no longer be joining the debate. The obvious explanation is that the arrowed quasar in the picture is behind the nearby galaxy and is in fact as far away as its redshift indicates. There are currently very, very few astronomers who continue to believe that quasars are nearby.

 

[Jonathan Scott]

Geoffrey Burbidge had this opinion (that quasar redshifts are not cosmological) for decades, and steadfastly refused to abandon it despite mountains of evidence to the contrary. Note that this article is from 2005, and that Geoffrey Burbidge has since passed away and so will no longer be joining the debate. The obvious explanation is that the arrowed quasar in the picture is behind the nearby galaxy and is in fact as far away as its redshift indicates. There are currently very, very few astronomers who continue to believe that quasars are nearby.

That explanation doesn't fit well with the quasar spectrum showing very little evidence of intervening material of the expected density along the line of sight at the appropriate redshift, although there could of course be a coincidental "thin patch" in the foreground galaxy along that line. It's true that a galaxy is nothing like as "solid" as it appears, but from what I've read about it (even from sceptics in this case) a line of sight that near to the core of a galaxy would normally be expected to show signs of much more intervening gas and dust, as has been observed in other cases where objects are seen through a foreground galaxy.

It appears that Morley B Bell in Canada is one astronomer who is still looking actively at the evidence; he has produced or co-authored several papers (search for M B Bell) analyzing quasar statistics and related observations which show that if you assume quasars redshifts are cosmological, the resulting explanations are complex and leave many unsolved puzzles, but if you assume the redshifts of young quasars have a large intrinsic component which decreases towards zero with time (as Arp claims) then all of these puzzles vanish and you suddenly only have one key thing to explain, the intrinsic redshift, for which there is admittedly thought to be no known explanation compatible with the standard interpretation of General Relativity.

Given that GR is already being adjusted heavily on galactic and cosmological scales by ideas involving dark matter and dark energy, I think that the chances are that quasars will demonstrate yet another case where we will eventually have to supplement or modify GR.

 

[bcrowell]

Given that GR is already being adjusted heavily on galactic and cosmological scales by ideas involving dark matter and dark energy, I think that the chances are that quasars will demonstrate yet another case where we will eventually have to supplement or modify GR.

This is incorrect. Dark matter and dark energy don't require any modifications to GR. The GR used in modern cosmological models is the same GR Einstein published in 1915.

 

[bcrowell]

It appears that Morley B Bell in Canada is one astronomer who is still looking actively at the evidence; he has produced or co-authored several papers (search for M B Bell) analyzing quasar statistics and related observations which show that if you assume quasars redshifts are cosmological, the resulting explanations are complex and leave many unsolved puzzles, but if you assume the redshifts of young quasars have a large intrinsic component which decreases towards zero with time (as Arp claims) then all of these puzzles vanish and you suddenly only have one key thing to explain, the intrinsic redshift, for which there is admittedly thought to be no known explanation compatible with the standard interpretation of General Relativity.

A search for his name on arxiv, http://arxiv.org/find/astro-ph/1/au:+Bell_M/0/1/0/all/0/1 , gives 31 results. Does one of these papers contain the claim that "if you assume quasars redshifts are cosmological, the resulting explanations are complex and leave many unsolved puzzles?"

 

[phyzguy]

... if you assume quasars redshifts are cosmological, the resulting explanations are complex and leave many unsolved puzzles ...

Please list at least one of the 'unsolved puzzles'.

 

[Shenstar]

Please list at least one of the 'unsolved puzzles'.

Isn't the accelerating expansion of the universe one of the unsolved puzzles which is linked to dark energy but not fully comprehended?

 

[bcrowell]

Isn't the accelerating expansion of the universe one of the unsolved puzzles which is linked to dark energy but not fully comprehended?

Jonathan Scott's statement was that the explanations were "complex and leave many unsolved puzzles." There is nothing complex about a nonzero value for the cosmological constant. It's just a term in the Einstein field equations. It's also to be expected based on quantum field theory that the value is nonzero -- we just don't understand why there are so many cancellations that make it as small as it actually is.

Jonathan Scott also said that the issues arise "if you assume quasars redshifts are cosmological." The main evidence for the nonzero cosmological constant comes from supernovae, not quasars.

 

[Jonathan Scott]

This is incorrect. Dark matter and dark energy don't require any modifications to GR. The GR used in modern cosmological models is the same GR Einstein published in 1915.

As you surely know, the concepts of dark matter and dark energy have arisen purely as an explanation for gravitational effects which are not explained by GR. This doesn't necessarily mean that GR is "wrong" but that it is not the whole story.

 

[Jonathan Scott]

A search for his name on arxiv, http://arxiv.org/find/astro-ph/1/au:+Bell_M/0/1/0/all/0/1 , gives 31 results. Does one of these papers contain the claim that "if you assume quasars redshifts are cosmological, the resulting explanations are complex and leave many unsolved puzzles?"

If you ignore the hits on "M.E.Bell" and "M.R.Bell" and just stick to "M.B.Bell" I think you'll find that just about every entry in that list relates to such ideas, although that was not a literal quote.

In one I've recently looked at, even the title supports it: arXiv:0812.3130v1 "The Peculiar Shape of the $\beta_{app} − z$ Distribution Seen in Radio Loud AGN Jets Is Explained Simply and Naturally In the Local Quasar Model". This paper considers why "superluminal" blobs (conventionally attributed to beaming effects) cut off in a strange way for quasars with smaller redshift.

There are also questions of why the density of lines at various redshifts in quasar redshifts is so weakly related to the overall redshift. This is just one of the characteristics that is conventionally partly explained by the "evolutionary" concept that quasars of different ages have different characteristics.

There are also the obvious questions of quasar distribution in space; there is a surprisingly spherical hole around us if we assume cosmological distances. Again, this is conventionally covered by an evolutionary model which says that quasars suddenly stopped existing everywhere at some relatively recent time.

Another aspect is the Arp's original observation that many quasars appear to be have been emitted, often in pairs, by large galaxies of much lower redshift, including most of the brighest quasars. As we only have one sky, it's difficult to evaluate the probability of this occurring by chance, but it certainly looks interesting.

I frequently hear statements that the idea of local quasars has been ruled out by the fact that some of them are surrounded by galaxies at the same redshift. However, this has always been consistent with Arp's original observation, which is that quasars closest to the host galaxy have high intrinsic redshifts and a point-like appearance, or unresolved nebulosity, but quasars further away have much smaller intrinsic redshifts and appear more like galaxies with active nuclei. Also, even if the surrounding material did appear to be a galaxy at the same redshift, this could still be just a matter of some unexplained intrinsic redshift of both the quasar and its surrounding galaxy; if it is possible to have intrinsic redshift in violation of what we expect from GR, we cannot use GR to rule it out at the galactic scale.

There are many other more technical complexities, for example relating to the "metallicity" shown in the spectrum failing to correlate with the evolutionary time scale, and "fingers of God" effects in the supposed spatial distribution.

Another very controversial observation is that the relative redshifts between quasars related to a given host galaxy seems to follow a specific approximate pattern. This might be explained for example by the idea that ejection speeds are relatively low (otherwise Doppler effects would hide this pattern) but ejections occur at regular intervals and the intrinsic redshifts decay in a curiously regular way. The official view is that this must be some form of selection effect in the way the observations are collected or processed, but such effects seem to be surprisingly common.

Explaining intrinsic redshift is very difficult, and current attempts are far too speculative to discuss here. However, on the other side, the cosmological distance view of quasars has been presenting a whole series of weird effects ever since they were discovered, and although we have come up with some sort of possible explanation for each one the problems keep coming.

 

[Chalnoth]

Jonathan Scott also said that the issues arise "if you assume quasars redshifts are cosmological." The main evidence for the nonzero cosmological constant comes from supernovae, not quasars.

Well, the main evidence comes from multiple, independent pieces of data all converging on the same cosmology. Quasars don't feature prominently, because they aren't terribly good for estimating cosmological distances. But we do have supernovae, the cosmic microwave background, baryon acoustic oscillations, and measurements of the nearby expansion rate.

 

[Jonathan Scott]

Well, the main evidence comes from multiple, independent pieces of data all converging on the same cosmology. Quasars don't feature prominently, because they aren't terribly good for estimating cosmological distances. But we do have supernovae, the cosmic microwave background, baryon acoustic oscillations, and measurements of the nearby expansion rate.

I don't think the quasar questions relate directly to any of those things. Redshift of normal galaxies would appear to be a reliable indicator of cosmological distance.

There just seems to be a special problem with many quasars apparently being related to much nearer objects, which would require them to have a significant (but theoretically "impossible") intrinsic redshift, and there are also similar cases for apparent satellite objects which look more like small galaxies than quasars, where the intrinsic redshift is however less extreme.

 

[Chalnoth]

I don't think the quasar questions relate directly to any of those things. Redshift of normal galaxies would appear to be a reliable indicator of cosmological distance.

There just seems to be a special problem with many quasars apparently being related to much nearer objects, which would require them to have a significant (but theoretically "impossible") intrinsic redshift, and there are also similar cases for apparent satellite objects which look more like small galaxies than quasars, where the intrinsic redshift is however less extreme.

There is no such coincidence problem when looked at properly. There is also no physical mechanism by which quasars can possibly have an intrinsic redshift while still being nearby.

 

[Jonathan Scott]

There is no such coincidence problem when looked at properly.

As Arp has previously pointed out many times, even if you just start from the brightest quasars in the sky (to avoid selection bias), there appears to be an obvious immediate relationship with major galaxies. As there's only one sky, it could just be a big coincidence, but it looks very plausible.

There is also no physical mechanism by which quasars can possibly have an intrinsic redshift while still being nearby.

I agree there is no KNOWN physical mechanism, but it's not a huge leap to imagine the possibility of one, and it doesn't require violating any major principles (unlike some of Arp's suggestions).

For example, if GR turns out to be sufficiently inaccurate in the very strong field regime that gravitational collapse does not occur, that would allow the existence of quasi-stellar objects with significant intrinsic gravitational redshifts (and such objects could also hold together when spinning at relativistic speeds). That in itself would not also allow surrounding material to have the same intrinsic redshift, but if the surrounding material is actually being illuminated or stimulated by intense radiation from the central object, that could well give an illusion of a matching redshift.

 

[Chalnoth]

As Arp has previously pointed out many times, even if you just start from the brightest quasars in the sky (to avoid selection bias), there appears to be an obvious immediate relationship with major galaxies. As there's only one sky, it could just be a big coincidence, but it looks very plausible.

This is just flat-out not true. There is no coincidence whatsoever. Go ahead, try to find evidence that this is the case. I dare you.

Oh, and let me also point out that we have now observed the host galaxies associated with many quasars, and the expected jets of matter that such quasars would produce if they were due to supermassive black holes at the centers of galaxies.

I agree there is no KNOWN physical mechanism, but it's not a huge leap to imagine the possibility of one, and it doesn't require violating any major principles (unlike some of Arp's suggestions).

Yes, it is a huge leap. A tremendous leap. An intrinsic redshift not related to velocity/gravity requires basically violating all of relativity and quantum mechanics.

 

[Shenstar]

To find out how near or far the quasars are, is it not possible to do some calculations based on gravitational lending, using objects directly behind the objects of view. I've seen some rare pictures of quasars gravitational lending galaxies behind them. The other way round is far more common.

With regards to redshift being intrinsic in some objects. All you would need to find is another case of why wavelengths can stretch. Can the spin, rotation, radiation emissions, movement, somehow show this is possible? Maybe some sort of simulation program can show this occurring.

 

[phyzguy]

Of course it's possible to do gravitational lensing studies of quasars, and this has been done many times. There are many examples of multiply imaged quasars which are lensed by intervening galaxies. Not only are the images of the quasars consistent with gravitational lensing, but the time delays between the different images are fully consistent with GR as well. Here is an example: http://arxiv.org/abs/astro-ph/0607513 . How anyone could look at these observations and conclude that quasars are not at cosmological distances is beyond me.

 

[Chalnoth]

To find out how near or far the quasars are, is it not possible to do some calculations based on gravitational lending, using objects directly behind the objects of view. I've seen some rare pictures of quasars gravitational lending galaxies behind them. The other way round is far more common.

Lensing doesn't give a very good estimate of the distance to the background (lensed) object, other than to show that the lensed object is significantly further away than the object that does the lensing. It does, however, provide information about the mass and mass distribution of the lensing object.

With regards to redshift being intrinsic in some objects. All you would need to find is another case of why wavelengths can stretch. Can the spin, rotation, radiation emissions, movement, somehow show this is possible? Maybe some sort of simulation program can show this occurring.

Spin and rotation are basically the same thing and tend to broaden spectral lines. There is very little overall redshift.

The idea of radiation emissions doing anything here makes no sense whatsoever because we're looking at radiation emissions.

For movement to be the cause, you'd have to believe that every quasar is thrown away from us at relativistic speeds from the nearby galaxy it's supposed to be associated with. That's just nonsensical.

There are only two ways to cause a redshift of spectral lines: relative velocity and gravitational redshift. That is it.

 

[Shenstar]

Thanks for that information. I was just throwing a few ideas out there so that you could answer them and clarify as you did.

Ive not seen all the conflicting data, but it appears from what you've said that those quasars must be behind the galaxies. There being so many of these formations in space that the possibility of them appearing as they do is not so improbable.

 

[Chalnoth]

Thanks for that information. I was just throwing a few ideas out there so that you could answer them and clarify as you did.

Ive not seen all the conflicting data, but it appears from what you've said that those quasars must be behind the galaxies. There being so many of these formations in space that the possibility of them appearing as they do is not so improbable.

There's also the point to be made that gravitational lensing magnifies background objects, so that a quasar that just happens to be located near a foreground galaxy is likely to be made brighter by the lensing due to the foreground galaxy. The effect of this lensing needs to be taken into account if you're going to try to seriously ask the question of whether foreground galaxies and quasars are actually related.

 

[Jonathan Scott]

This is just flat-out not true. There is no coincidence whatsoever. Go ahead, try to find evidence that this is the case. I dare you.

What do you mean "no coincidence"? By "coincidence" I would mean that the apparent patterns visible in the distribution of quasars were purely chance, so I would expect your position to be that it WAS purely coincidence.

Have you looked at Arp's charts? Most of the lines and pairings seem quite obvious, and he includes all other similar quasars where relevant to show that he's not just picking out ones that show the pattern. I remember from some astronomy magazine many years ago being astonished to see Arp pointing out that even 3C273 seems to have been ejected from M49, with signs of a faint connection between the two.

It is admittedly difficult to evaluate the probabilities behind such patterns, given that it's not easy to define objectively what one would consider an "unlikely" grouping, but Arp makes some plausible attempts which suggest that the observed connections are really quite extraordinarily unlikely if all the bright quasars are background objects.

Oh, and let me also point out that we have now observed the host galaxies associated with many quasars, ...

As I previously mentioned, according to Arp's conclusions from his observations, host galaxies with similar redshifts are expected around mature quasars, and such quasars are expected to be at or near their cosmological redshift distances, for example as seen in gravitational lensing cases.

However, young quasars would have an intrinsic redshift that would conventionally place them many times further away, so the apparent size of any nebulosity would be assumed to be much larger and it is not clear whether this might look like a galaxy even when unresolved. A mid-life quasar is very bright so that even if there is any nebulosity around it, it is difficult to obtain an independent spectrum, and even if that proves possible, it seems quite likely that the spectrum could be distorted by the radiation from the quasar itself.

... and the expected jets of matter that such quasars would produce if they were due to supermassive black holes at the centers of galaxies.

Jets of matter are actually much easier to explain if the supermassive objects are NOT black holes, because they could then easily have magnetic fields which are many orders of magnitude greater than that expected for a black hole (by the "no hair" theorem) or even an accretion disk. There are theories that a black hole could hold a "fossilized" magnetic field which might be sufficient for the purpose, but that's quite a stretch.

Yes, it is a huge leap. A tremendous leap. An intrinsic redshift not related to velocity/gravity requires basically violating all of relativity and quantum mechanics.

I didn't say not related to velocity/gravity. I pointed out that it could be related to gravity if collapse doesn't occur, which only requires a change to GR in a most extreme regime.

 

[TrickyDicky]

What is approximately the threshold for a distance to be considered "cosmological"?

 

[Jonathan Scott]

What is approximately the threshold for a distance to be considered "cosmological"?

It's not a threshold. The question is whether the redshift of quasars is taken to be purely due to their distance (following the usual cosmological redshift distance law) or whether a significant part of the redshift is intrinsic to the quasar.

 

[TrickyDicky]

It's not a threshold. The question is whether the redshift of quasars is taken to be purely due to their distance (following the usual cosmological redshift distance law) or whether a significant part of the redshift is intrinsic to the quasar.

I know, I was thinking in terms of how near a quasar could be according to the concordance model.

BTW, have you heard of the Wolf shift as a possible mechanism of intrinsic redshift?

 

[Jonathan Scott]

BTW, have you heard of the Wolf shift as a possible mechanism of intrinsic redshift?

It doesn't seem very plausible to me. You can use it to shift one spectral line of coherent light in the lab, but I don't think it can be used to shift a whole spectrum, and bright quasars typically show multiple identifiable lines.

 

[bcrowell]

In one I've recently looked at, even the title supports it: arXiv:0812.3130v1 "The Peculiar Shape of the $\beta_{app} − z$ Distribution Seen in Radio Loud AGN Jets Is Explained Simply and Naturally In the Local Quasar Model".

As far as I can tell from the arxiv page and the pdf, this paper hasn't been published in a peer-reviewed journal. I have no technical expertise in observational astronomy, but the fact that it was posted in 2008 and never published suggests that it's an incorrect paper that failed to make it through peer review. Please note that according to the PF rules:

It is against our Posting Guidelines to discuss, in most of the PF forums or in blogs, 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.

Can you provide any support for your claims from anything that has passed peer review?

However, this has always been consistent with Arp's original observation, which is that quasars closest to the host galaxy have high intrinsic redshifts and a point-like appearance, or unresolved nebulosity, but quasars further away have much smaller intrinsic redshifts and appear more like galaxies with active nuclei.

You refer to the "observation" that there are "intrinsic redshifts." The use of the word "observation" might mislead folks into thinking that the existence of "intrinsic redshifts" has actually been verified observationally in a way that is accepted as objectively reliable by people in the field. This is not the case. Claims of "intrinsic redshifts" are crackpot material.

Explaining intrinsic redshift is very difficult, and current attempts are far too speculative to discuss here.

Again there is a problem with your use of language. When you say "Explaining intrinsic redshift" you make it sound as though there is an objectively established phenomenon, which then requires explanation. The overwhelming consensus in the field is that there is no such thing as an "intrinsic redshift."

-Ben

 

[George Jones]

Since this thread has run its course and is veering into the highly speculative and non-mainstream, it is now closed.

From the Physics Forums Rule, to which all registrants agree:

Overly Speculative Posts: One of the main goals of PF is to help students learn the current status of physics as practiced by the scientific community; accordingly, Physicsforums.com strives to maintain high standards of academic integrity. There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in most of the PF forums or in blogs, 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.