Quasars: A Different Perspective?

[Jonathan Scott]

It seems that there is overwhelming experimental evidence that at least some quasars must have significant intrinsic redshifts (as Arp has been suggesting for years). There is also some evidence from a gravitationally lensed quasar suggesting a significant intrinsic magnetic field. These observations are not compatible with the black hole model derived from the standard interpretation of GR.

This seems to me to be evidence that the standard interpretation of GR is incorrect. However, it appears that the official line is currently that GR theory is so strong that it cannot be countered by experimental evidence, so there must be some additional effect which is not being taken into account (like dark matter and dark energy). In the case of quasars, it is a statistically unlikely evolution of characteristics with time which just happens to duplicate the weird radial distribution implied by their redshifts. GR just seems to be too tough for Occam's razor!

I have seen some fairly convincing papers (by Salvatore Antoci et al) which suggest that even though Einstein's GR and the original Schwarzschild solution are correct, black holes only arise as a result of a mathematical change made by Hilbert. With Schwarzschild's original solution, quasars could be hyper-massive objects with well-defined surfaces and unlimited intrinsic redshift, probably spinning at relativistic speeds, at least when first formed. There would then be little need for any special time evolution of the quasar population, as most of them would fall into the same range of properties.

I'm aware that a few quasars have been shown to be at or near their redshift distances by various means. However, according to Arp's plausible observations (ignoring his implausible theories), only the youngest and most active have significant intrinsic redshifts. These appear to decrease with time, and it appears that old quasars probably evolve into galaxies with redshifts approximately corresponding to distance as usual.

 

[Hurkyl]

Schwarzschild's solution has a hole too. The difference is that Schwarzschild's hole is formed by cutting out what we usually the event horizon, along with everything inside, and the 'boundary' of the hole has the geometry of a sphere of finite, nonzero area.

(I put 'boundary' in quotes, because I'm really referring to the region of space-time surrounding the hole)

(I said 'geometry' not 'coordinate representation'. The hole is not part of space-time, so a faux-coordinate chart for the region surrounding the hole can 'fill it in' with whatever contractible shape it wants to use, because the 'filled in' portion isn't meant to have any relationship with space-time)


GR has no explicit prohobition against putting holes whever you want in space-time. e.g. observations are perfectly consistent with there being a hole in space-time where we think the moon is, but the hole simply emits light and stuff to give the appearance of the moon. But as you can imagine, physicists generally avoid introducing holes gratuitously, and only do it when it's really necessary.

 

[Jonathan Scott]

Schwarzschild's solution has a hole too. The difference is that Schwarzschild's hole is formed by cutting out what we usually the event horizon, along with everything inside, and the 'boundary' of the hole has the geometry of a sphere of finite, nonzero area.

(I put 'boundary' in quotes, because I'm really referring to the region of space-time surrounding the hole)

(I said 'geometry' not 'coordinate representation'. The hole is not part of space-time, so a faux-coordinate chart for the region surrounding the hole can 'fill it in' with whatever contractible shape it wants to use, because the 'filled in' portion isn't meant to have any relationship with space-time)GR has no explicit prohobition against putting holes whever you want in space-time. e.g. observations are perfectly consistent with there being a hole in space-time where we think the moon is, but the hole simply emits light and stuff to give the appearance of the moon. But as you can imagine, physicists generally avoid introducing holes gratuitously, and only do it when it's really necessary.

I don't think your assertions above are correct, but this isn't the place to discuss the radial coordinate interpretation, especially since a thread on it has been locked by George Jones over in the relativity forum.

[Edit by George]The thread

https://www.physicsforums.com/showthread.php?t=272909

will be opened sometime later today.[/EDIT]

My main point is that the observational evidence suggests an alternative explanation for quasars, even if that implies that GR needs fixing in some way (of which I have given a specific example).

 

[Nereid]

It seems that there is overwhelming experimental evidence that at least some quasars must have significant intrinsic redshifts (as Arp has been suggesting for years).

Really?

I've seen many claims to this effect, over several years and in several fora, but have yet to see a strong case presented for it, backed by the usual requirements^.

Rather than derail this thread, why don't you start another one, with a very clearly stated scope, and I'll happily join?

There is also some evidence from a gravitationally lensed quasar suggesting a significant intrinsic magnetic field.

Source(s)?

These observations are not compatible with the black hole model derived from the standard interpretation of GR.

Oh?

First, can you back this claim with relevant sources?

Next, are you prepared to discuss it^?

This seems to me to be evidence that the standard interpretation of GR is incorrect.

OK, that's your opinion.

Mine is that there is nothing in your claims.

Let's discuss (in a separate thread).

However, it appears that the official line is currently that GR theory is so strong that it cannot be countered by experimental evidence, so there must be some additional effect which is not being taken into account (like dark matter and dark energy).

Oh please!

From your posting record here in PF, JS, I'd've expected better than this.

It's bad enough that this gross mischaracterisation of modern cosmology appears on crackpot websites; it's worse that long-time PFers are still repeating it.

Would you be, genuinely, interesting in discussing just how distorted this characterisation is?

In the case of quasars, it is a statistically unlikely evolution of characteristics with time which just happens to duplicate the weird radial distribution implied by their redshifts. GR just seems to be too tough for Occam's razor!

What do you mean?

This seems to be a statement devoid of any serious relationship to the vast body of observational data concerning quasars.

I have seen some fairly convincing papers (by Salvatore Antoci et al) which suggest that even though Einstein's GR and the original Schwarzschild solution are correct, black holes only arise as a result of a mathematical change made by Hilbert. With Schwarzschild's original solution, quasars could be hyper-massive objects with well-defined surfaces and unlimited intrinsic redshift, probably spinning at relativistic speeds, at least when first formed. There would then be little need for any special time evolution of the quasar population, as most of them would fall into the same range of properties.

Surely the place to discuss this is in the S&GR section of PF, not the Cosmology one?

I'm aware that a few quasars have been shown to be at or near their redshift distances by various means. However, according to Arp's plausible observations (ignoring his implausible theories), only the youngest and most active have significant intrinsic redshifts. These appear to decrease with time, and it appears that old quasars probably evolve into galaxies with redshifts approximately corresponding to distance as usual.

I look forward to your new thread ...


^ per PF's rules, peer-reviewed papers published in relevant journals

 

[Jonathan Scott]

There are already lots of well-known strange features of quasars, such as luminosities which are hard to explain by any theory and which apparently evolve throughout the life so far of the universe in a way which requires multiple parameters to explain (and imply that quasars have conveniently "turned off" recently). There are also of course Arp's observations that most of the brightest quasars fall into lines either side of a particular type of galaxy, where the closest ones have high relative redshifts but the most distant ones have similar redshifts to the central galaxy, and there are often hydrogen clouds scattered along the same lines. The new information about the metallicities of high-redshift quasars which turbo-1 referenced in the opening post of this thread adds to this pattern. Perhaps no one point proves anything, but all of this strongly suggests that a simpler explanation would be that some of the redshift is intrinsic.

The gravitationally lensed quasar case is the one referenced in the "Black Holes or MECO" paper by R Schild of which a preprint is available at http://arxiv.org/abs/0806.1748" , where he presents evidence for a strong magnetic field between the quasar and the surrounding material. I cannot comment on the strength of this evidence. However, it is well known that a black hole cannot have a strong intrinsic magnetic field because of the "no hair" theorem, because the only charge it can contain is unbalanced charge (which tends to self-neutralize anyway by preferentially attracting oppositely-charged matter), and the circulation of that in a rotating black hole cannot create any significant magnetic field at all.

The apparent magnetic field of the gravitationally lensed quasar is used as evidence in support of the "MECO" (magnetospherical eternally collapsing object) theory of Abhas Mitra and others, but I don't find that plausible. Instead, I think it's a lot simpler and black holes are an artefact of Hilbert simplifying the maths without realizing the implications, as described by Salvatore Antoci and others in a paper "Reinstating Schwarzschild's Original Solution" of which there is a preprint at http://arxiv.org/abs/gr-qc/0406090" .

Within GR black hole theory it is possible for a small amount of intrinsic redshift to arise from the gravitational redshift of the inner edge of an accretion disk at the closest stable orbit. However, this effect is not capable of giving rise to the sort of intrinsic redshift that would be needed to adjust the apparent distances of the brightest quasars to make them more uniformly distributed, nor to make them match the redshifts of the apparent host galaxies according to Arp. This is a well-known argument which has been used as the basis for the standard claim that Arp's observations must be coincidences because GR doesn't allow intrinsic redshift at that level.

I hope that discussions on the validity of the original Schwarzschild solution will resume eventually on the S&GR forum, if and when George Jones permits it. That topic is quite tricky, as Schwarzschild's initial assumption of a point mass is seriously unphysical and does very nasty things to coordinates, and I've been having a lot of difficulty understanding it. However, what shocked me most about the topic is that it appears that the standard answer to any question relating to the relevant physics or mathematics (on these forums or anywhere else) seems to be defensiveness, anger and abuse.[Edit by George]The thread

https://www.physicsforums.com/showthread.php?t=272909

will be opened sometime later today.[/EDIT]

The point about the Schwarzschild radial coordinate is not the point here, anyway. I mainly wish to show strong agreement with the idea that the official ideas about quasars seem increasingly contrived and that it is surely time to investigate alternatives, starting from what we actually see. Arp's observations are very convincing (unlike his theories) - nearly ALL the known bright quasars line up across "host" galaxies and have red shifts where the closest quasars to the host galaxy have the largest difference in red shifts and appear to be the most active, and the further ones look more like galaxies and have similar redshifts to the "host" galaxy.

Although GR is very neat, and has been experimentally verified in the solar system to high accuracy, as I become more familiar with it I am becoming quite sceptical about it, and I feel it's probably just another approximation. In particular, if you look at the neat ideas in Dennis Sciama's 1953 "Origin of Inertia" paper http://adsabs.harvard.edu/abs/1953MNRAS.113...34S" where inertia and rotational effects arise naturally and trivially from the gravitational effect of the universe by analogy with electromagnetism, fully satisfying Mach's principle, it's very disturbing and dissatisfying that GR can be proved to be theoretically incompatible with Mach's principle (as Einstein demonstrated) while at the same time showing frame-dragging effects of exactly the right order of magnitude.

I therefore think GR should be treated like other physical theories as a work in progress, rather than being given what appears to be disproportionate reverence. However, this doesn't seem to be possible. Perhaps GR is such a mathematical subject that the people who study it are mostly mathematicians rather than physicists.

I'm now planning to try to learn more about detailed quasar spectral features, to see whether they perhaps fit the idea of an object with a relativistically spinning surface better than an accretion disk.

 

[Jonathan Scott]

Jonathan, I asked you to start a new thread if you want to discuss Arp, quasar intrinsic redshifts, etc.

I also asked you to discuss GR-related aspects in the S&GR section.

Would you be kind enough to say why you chose, instead, to hijack this thread?

I don't want to start any new discussion at this point. I was originally specifically responding to the point implied by the original post that it is hard to explain metallicities of high redshift quasars, by pointing out that the old idea that quasars have intrinsic redshift is primarily ruled out only by taking GR to untested limits, and seems worth revisiting, especially as I've recently seen papers which suggest that black hole theory is incorrect (which is of course a topic for S&GR, and I already have a thread on that, but George locked it some weeks ago to give himself a chance to respond). Apart from that, I was only answering specific questions.

I'm not an expert on quasars. I've seen Arp's stuff since many years ago. His observations are fascinating but his theories to explain them don't make any sense to me. My area of interest is relativity; SR is simple and totally robust, and GR is also quite neat in concept, but the more I get to know, the more I suspect that we are missing something important.

 

[Nereid]

I don't want to start any new discussion at this point. I was originally specifically responding to the point implied by the original post that it is hard to explain metallicities of high redshift quasars, by pointing out that the old idea that quasars have intrinsic redshift is primarily ruled out only by taking GR to untested limits,
[...]

Which is, of course, nonsense (so no need to comment further on your post); the idea that quasars have "intrinsic redshifts" is "ruled out" by application of many parts of the physics textbook, and standard techniques in astronomy. If you think that "taking GR to untested limits" plays a key ("primary") role in this, you simply haven't been paying attention.

I'm not an expert on quasars. I've seen Arp's stuff since many years ago. His observations are fascinating but his theories to explain them don't make any sense to me. My area of interest is relativity; SR is simple and totally robust, and GR is also quite neat in concept, but the more I get to know, the more I suspect that we are missing something important.

I look forward to reading your posts in the S&GR section.

 

[Nereid]

Missed this bit (it's quite important)

[...]

I'm not an expert on quasars. I've seen Arp's stuff since many years ago. His observations are fascinating but his theories to explain them don't make any sense to me. [...]

(bold added)

Yeah, and quantum mechanics (or parts of it) didn't make sense to Einstein (apparently).

Weird isn't it? Instead of saying "but his ideas seemed to be inconsistent with the totality of the pertinent observational results, and/or internally inconsistent, and/or inconsistent with SR/QM/whatever" (or something like this), as a reason to put Arp's ideas on quasars in the round file, you used one of the least scientific reasons (essentially, Argument from Incredulity).

May I infer from this that a response to your ideas on GR can be powerfully rebutted with "but JS's ideas on GR don't make any sense to me (Nereid)"?

 

[Nereid]

Why quasars have no "intrinsic redshift"

Why quasars have no "intrinsic redshift"

In a phrase, because quasars are merely one kind of AGN (active galactic nucleus).

One of the big advances in quasar research was the formulation of http://www.mssl.ucl.ac.uk/www_astro/agn/agn_unified.html" *. An enormous amount of work has been done confirming (and modifying) this; the net - so far as "quasar intrinsic redshift" is concerned - is that quasars have the same redshifts as galaxies do.

For a great many AGNs, including many quasars, the redshift of both the nucleus and the host galaxy of which it is the nucleus can, and has, been measured; no systematic differences have been reported.

There are many other sets of observation and logic chains which are consistent with the "no quasar intrinsic redshift" conclusion; broadly, these are independent of those underlying the 'unified AGN model' ones.

Pace JS, no application of GR is involved^.

* my quick search turned up http://cdsads.u-strasbg.fr/abs/1987PASP...99..309L".

^ with perhaps just one exception: lensed quasars. However this has nothing to do with JS' point (above), and in any case it applies equally to galaxies, clusters of galaxies, etc (so to be consistent, JS would have to claim that every object beyond the Local Group has an "intrinsic redshift"!)

 

[Jonathan Scott]

Missed this bit (it's quite important)(bold added)

Yeah, and quantum mechanics (or parts of it) didn't make sense to Einstein (apparently).

Weird isn't it? Instead of saying "but his ideas seemed to be inconsistent with the totality of the pertinent observational results, and/or internally inconsistent, and/or inconsistent with SR/QM/whatever" (or something like this), as a reason to put Arp's ideas on quasars in the round file, you used one of the least scientific reasons (essentially, Argument from Incredulity).

May I infer from this that a response to your ideas on GR can be powerfully rebutted with "but JS's ideas on GR don't make any sense to me (Nereid)"?

Arp's theories (at the time I read his books) were based on an idea that "young mass" is somehow different from "old mass", and somehow has an intrinsic redshift. That's about as scientific as it got, which is why I don't reckon it makes sense. It's certainly a lot less scientific than MOND, for example.

The only specific problem in GR which I've been mentioning here was not identified by me but by several others (starting with Marcel Brillouin in 1923 and currently being raised by Salvatore Antoci), and is based on the idea that Einstein's GR and Schwarzschild original solution were totally right but Hilbert's "simplification" of Schwarzschild's solution appears to have introduced black holes. Unfortunately it's not as clear as that because Schwarzschild's original solution relies on the unphysical concept of a point mass. There may be some more discussion on that over on S&GR soon.

Apart from that, I have major suspicions that GR is missing something, especially in relation to Mach's principle, but I don't have a specific way of fixing it. I have however been trying to look at many aspects of the relationships between GR and relativistic extensions of classical theories of gravity and electromagnetism in order to try to obtain a better understanding of GR from all possible viewpoints.

I've not been keeping up to date with the evidence that quasars are at their redshift distances, but when I was previously looking at the arguments against Arp's interpretation of his observations, I noticed that many of those arguments appeared to be somewhat circular. For example, if you interpret the Lyman forest as being entirely due to clouds spread across the universe, then obviously the quasar is beyond them, but if you interpret part of it as being due to clouds in a highly redshifted environment in the vicinity of the quasar then it has very little to say about the distance unless you have some other way of distinguishing a boundary between the two parts.

I've seen a paper, arXiv:astro-ph/0005006v1 "Evidence consistent with the cosmological interpretation of quasar redshifts", which claims to demonstrate that the redshift is real by the fact that almost all of the quasar absorption lines for a random selection of quasars are at a lower redshift than the emission lines. I cannot understand how they think this proves anything, as this would apply even if there was intrinsic redshift. If anyone knows why this is considered relevant, I'd be interested to know. I found it quite surprising that there are several well-known cases where in which absorption systems appear to be slightly more redshifted than the emission systems, and I would have thought that those would be a better argument against intrinsic redshift than the reverse!

Apart from that, even by Arp's observations, I thought that only the youngest and brightest quasars were thought to have significant intrinsic redshift, so a lack of intrinsic redshift for specific cases might not be a very strong argument.

Arp also suggests that in some cases some older quasars have started to show surrounding material like an ordinary galaxy but that material has the same redshift as the quasar which is still measurably different from the original "host galaxy". The only mechanism which I know that could do this is for the whole galaxy to have a sufficiently relativistic speed to cause time dilation, but for that to work in multiple cases requires some coincidences. (However, that might be no worse than for the "superluminal jets" from multiple quasars which I believe are usually explained by assuming that they are directed nearly towards us and that some selection effect makes it much easier for us to see those than ones which are moving away).

Overall, I simply feel that the current quasar and cosmological models are far too contrived and complex, with too many coincidences and oddities. Although GR is surprisingly neat and simple, I suspect firstly that black holes are a mistake (which would eliminate a lot of oddities in one go) and that secondly we are somehow looking at it in the wrong way and missing something important, probably linked to Mach's principle. I can't say how to fix the problems, but I feel that there should be more openness to the possibility that GR isn't working as well as it should.

 

[Nereid]

Once again, I'm going to ignore the parts of this post that don't really belong in this thread (or even this section).

Arp's theories (at the time I read his books) were based on an idea that "young mass" is somehow different from "old mass", and somehow has an intrinsic redshift. That's about as scientific as it got, which is why I don't reckon it makes sense. It's certainly a lot less scientific than MOND, for example.

You seem to have confirmed - again - that you are approaching this from a perspective that is not scientific!

How about the extent to which Arp's ideas are consistent with the collective body of pertinent astronomical observations? Doesn't that count for anything, in your approach to deciding whether his ideas have legs or not?

Apart from that, I have major suspicions that GR is missing something, especially in relation to Mach's principle, but I don't have a specific way of fixing it. I have however been trying to look at many aspects of the relationships between GR and relativistic extensions of classical theories of gravity and electromagnetism in order to try to obtain a better understanding of GR from all possible viewpoints.

That's nice, but surely this sort of thing is an explicit violation of the PF rules?

I've not been keeping up to date with the evidence that quasars are at their redshift distances,

Hold on! Didn't you just make a subtle, but important, modification to your earlier claims?

but when I was previously looking at the arguments against Arp's interpretation of his observations, I noticed that many of those arguments appeared to be somewhat circular. For example, if you interpret the Lyman forest as being entirely due to clouds spread across the universe, then obviously the quasar is beyond them, but if you interpret part of it as being due to clouds in a highly redshifted environment in the vicinity of the quasar then it has very little to say about the distance unless you have some other way of distinguishing a boundary between the two parts.

Did you read my last post, JS? Or did they cross in the night?

If you are serious about this "somewhat circular" claim, please have the honesty (and courage?) to declare your preparedness to research, and defend, it.

If not, shut up (pardon me for being so blunt, but I have close to zero tolerance for drive-by anti-science).

I've seen a paper, arXiv:astro-ph/0005006v1 "Evidence consistent with the cosmological interpretation of quasar redshifts", which claims to demonstrate that the redshift is real by the fact that almost all of the quasar absorption lines for a random selection of quasars are at a lower redshift than the emission lines. I cannot understand how they think this proves anything, as this would apply even if there was intrinsic redshift. If anyone knows why this is considered relevant, I'd be interested to know.

Maybe we could start with the abstract, and focus on what it actually says, rather than the strawman you have constructed?

In this letter, the old issue of whether redshifts of quasars are of cosmological origin is investigated. We make a plot of absorption redshifts versus emission redshifts for quasars with large amounts of data. Our study shows that, almost all absorption redshifts are smaller than the corresponding emission redshifts. The relation between the absorption and emission redshifts predicted by current cosmological models is well obeyed. The result confirms that redshifts of quasars are indeed distance indicators. It might be the most obvious evidence found so far to be consistent with the cosmological interpretation of quasar redshifts.

Notice the absence of the word "proves"?

Notice what the authors actually say they have confirmed ("The relation between the absorption and emission redshifts predicted by current cosmological models is well obeyed. The result confirms that redshifts of quasars are indeed distance indicators")?

But, perhaps, I misunderstood your logic/claim/whatever; would you care to expand/clarify please?

I found it quite surprising that there are several well-known cases where in which absorption systems appear to be slightly more redshifted than the emission systems, and I would have thought that those would be a better argument against intrinsic redshift than the reverse!

Source and details please.

Apart from that, even by Arp's observations, I thought that only the youngest and brightest quasars were thought to have significant intrinsic redshift, so a lack of intrinsic redshift for specific cases might not be a very strong argument.

(bold added)

Well, how about you go dig up that book you think you remember reading (or paper or whatever), cite it, and quote the relevant passages?

How can anyone have a discussion with you if all you do is spout such vague stuff?

Arp also suggests that in some cases some older quasars have started to show surrounding material like an ordinary galaxy but that material has the same redshift as the quasar which is still measurably different from the original "host galaxy".

He does?

Where? As in, in which publication in a relevant peer-reviewed journal?

The only mechanism which I know that could do this is for the whole galaxy to have a sufficiently relativistic speed to cause time dilation, but for that to work in multiple cases requires some coincidences. (However, that might be no worse than for the "superluminal jets" from multiple quasars which I believe are usually explained by assuming that they are directed nearly towards us and that some selection effect makes it much easier for us to see those than ones which are moving away).

Enough of this waffle!

Please quote your sources!

Overall, I simply feel that the current quasar and cosmological models are far too contrived and complex, with too many coincidences and oddities.

And I feel that JS has hoist himself so far up his own petard that I can't figure out why I'm even bothering to write this.

Worse, IMHO, what JS has written, in this thread alone, is prima facie evidence of an anti-scientific approach ... or, perhaps at best, evidence of a serious lack of critical thinking.

Although GR is surprisingly neat and simple, I suspect firstly that black holes are a mistake (which would eliminate a lot of oddities in one go) and that secondly we are somehow looking at it in the wrong way and missing something important, probably linked to Mach's principle. I can't say how to fix the problems, but I feel that there should be more openness to the possibility that GR isn't working as well as it should.

And I think you should "put up or shut up".

Two opinions, no dialogue, right?

 

[Jonathan Scott]

It's just occurred to me (at 1am here) that there is an obvious and trivial case in which absorption systems are slightly more redshifted than emission ones, which is when the emission occurs from the surface of a body and the absorption occurs in material which is in low orbit around that body, as the time-dilation due to higher velocity in the orbiting material will create some additional redshift.

No similar effect can occur with accretion disks because the velocity of the material decreases with distance from the centre, so the time dilations due to gravitational potential and velocity both increase the redshift towards the centre.

For examples of this anomalous effect, see the paper I previous mentioned. The paragraph previously quoted includes the following:

Our study shows that, almost all absorption redshifts are smaller than the corresponding emission redshifts.

Within the paper, it gives more details:

In this sample, there are 66 sources (16.5% of the total) having one or more of their absorption redshifts larger than the emission redshifts. We call such sources as “anomalous sources”.

I also just found an old paper (from 1997) with the title "A spectroscopic study of selected quasars with absorption redshifts greater than emission redshifts", which is available online via http://adsabs.harvard.edu/abs/1977ApJ...213..619W".

 

[Jonathan Scott]

Most of what I've read of Arp's stuff comes from his book "Quasars, Redshifts and Controversies" and articles published long ago in astronomy magazines. I've also occasionally checked up on various web sites for any news. I have not recently reread the book (I'd have to dig out my copy), nor have I got a copy of the more recent "Seeing Red" book.

At the time, I checked out all the arguments I could both ways, as far as possible. I felt that his observations and his interpretation that certain galaxies emitted quasars which start off with a significant intrinsic redshift then age back towards the redshift of the host galaxy seemed to make a lot of sense. However, his personal theories as to how this could happen (in terms of "young mass" and "older mass", if I'm remembering correctly) seemed to totally disregard established theory, to the extent that I couldn't make any connection with GR or any other scientific theory of space and time.

I have not had time to be interested in the subject in the last few years, and the only thing that has triggered a new mention here is the papers in the last few years which raise the shocking possibility that black holes are a mathematical accident. The details of that discussion belong in S&GR, but for me this immediately raised again the question of quasar models and intrinsic redshifts.

I would like to get more up to date on the latest position on the well-known earlier anomalies (for example apparently superluminal jets and relationships to galaxies with lower redshift), so if you can suggest any appropriate source of information I'd be grateful.

 

[Nereid]

It's just occurred to me (at 1am here) that there is an obvious and trivial case in which absorption systems are slightly more redshifted than emission ones, which is when the emission occurs from the surface of a body and the absorption occurs in material which is in low orbit around that body, as the time-dilation due to higher velocity in the orbiting material will create some additional redshift.

No similar effect can occur with accretion disks because the velocity of the material decreases with distance from the centre, so the time dilations due to gravitational potential and velocity both increase the redshift towards the centre.

You might consider taking some realistic test cases and plugging in the numbers.

For starters, remember that, traditionally, quasars were point objects (on the sky), so what's observed is an integrated spectrum. And very early on the sky distribution of quasars pretty clearly showed they are extra-galactic.

So, at a distance of, say, 1, 10, 100, and 1,000 Mpc (megaparsecs), what is the radius of an orbit, or accretion disk, that is (just) <1"? What is the mass of a central object that could cause 'time dilation redshift' of 100 km/sec (say), at each of these radii?

In the case of orbiting material, whether accretion disk or not, how broad would the absorption system lines be, due to the integrated speeds of the material (assuming it is in quasi-stable orbits)? How does this line-width compare with the 'time dilation redshift'? Again, assume objects sufficiently massive as to be interesting, and with sufficient luminosities so as to correspond to the observed magnitudes of quasars ... oh, and make sure your toy systems do not exceed the Eddington limit.

For examples of this anomalous effect, see the paper I previous mentioned. The paragraph previously quoted includes the following:



Within the paper, it gives more details:

Let's take a closer look at this Qin et al. paper, shall we?

First, do you understand the point about absorption systems needing to be backlit by emission sources? IOW, in any 'quasar', whatever is causing the absorption lines, it must be in the foreground (between us and the emission source)?

Can you think of any physically plausible circumstances, for extragalactic objects, where this would not be the case?

I also just found an old paper (from 1997) with the title "A spectroscopic study of selected quasars with absorption redshifts greater than emission redshifts", which is available online via http://adsabs.harvard.edu/abs/1977ApJ...213..619W".

Indeed ... if the emission source is in a (rich) cluster (of galaxies), and a cloud of gas is in the same cluster - giving rise to an absorption system - the absorption lines may have a higher redshift than the emission ones. Can you work out why? And can you make an OOM (order of magnitude) estimate of a plausible maximum for such a z_abs > z_em case?

 

[Nereid]

Most of what I've read of Arp's stuff comes from his book "Quasars, Redshifts and Controversies" and articles published long ago in astronomy magazines. I've also occasionally checked up on various web sites for any news. I have not recently reread the book (I'd have to dig out my copy), nor have I got a copy of the more recent "Seeing Red" book.

Which would not be very helpful, here in PF, would it?

I mean, PF does not accept the use of such sources ... but perhaps these contain references to papers published in relevant peer-reviewed journals? You could read those, as a start, couldn't you?

At the time, I checked out all the arguments I could both ways, as far as possible. I felt that his observations and his interpretation that certain galaxies emitted quasars which start off with a significant intrinsic redshift then age back towards the redshift of the host galaxy seemed to make a lot of sense. However, his personal theories as to how this could happen (in terms of "young mass" and "older mass", if I'm remembering correctly) seemed to totally disregard established theory, to the extent that I couldn't make any connection with GR or any other scientific theory of space and time.

I have not had time to be interested in the subject in the last few years, and the only thing that has triggered a new mention here is the papers in the last few years which raise the shocking possibility that black holes are a mathematical accident. The details of that discussion belong in S&GR, but for me this immediately raised again the question of quasar models and intrinsic redshifts.

And as I have already said, unless there's a great deal more than what you've written so far, your (apparent) failure to apply even a modicum of critical thinking, to this question so raised, is shocking (to me anyway).

But let's see how you go with the toy models I outlined above ...

I would like to get more up to date on the latest position on the well-known earlier anomalies (for example apparently superluminal jets and relationships to galaxies with lower redshift), so if you can suggest any appropriate source of information I'd be grateful.

Sure thing.

Why not start http://cdsads.u-strasbg.fr/abstract_service.html" ?

 

[Jonathan Scott]

You might consider taking some realistic test cases and plugging in the numbers.

As a basic sanity check, I already took the example of PKS 0119-04 from the 1977 paper, which has a delta v of about 0.009c, which I'll round up to 0.01c. This would appear to be trivially achievable by a stable low orbit around a supermassive object, because if black holes did not happen, the object could be large enough that its surface is not far below the orbit and the gravitational potential of the surface is similar to that of the orbit. However, magnetic fields and electromagnetic interactions could make the orbit environment more complex than for a black hole.

So, at a distance of, say, 1, 10, 100, and 1,000 Mpc (megaparsecs), what is the radius of an orbit, or accretion disk, that is (just) <1"? What is the mass of a central object that could cause 'time dilation redshift' of 100 km/sec (say), at each of these radii?

I'm not sure what the basis is here for these suggestions; are you referring to some observed characteristics of specific quasars? I'm aware that an apparent accretion disk has been seen (by subtracting unpolarized light) - are you referring to that particular case?

An absorption system which is at a higher redshift would be the innermost cloud or ring. If the central object was not a black hole, I don't think the disk would necessarily be continuous, but would be affected for example by magnetic fields which could cause it to form separate bands. It might not even be particularly stable.

If black holes do not occur, then the quasar is effectively a hyper-massive star (probably spinning very fast, significantly smearing the emission spectrum by doppler effects, although if we are seeing it from above a pole, the smearing could be significantly decreased). It can also have a significant intrinsic redshift, making it closer than it appears. Both of these factors mean that less extreme physics is needed to achieve the required luminosity.

Let's take a closer look at this Qin et al. paper, shall we?

First, do you understand the point about absorption systems needing to be backlit by emission sources? IOW, in any 'quasar', whatever is causing the absorption lines, it must be in the foreground (between us and the emission source)?

Can you think of any physically plausible circumstances, for extragalactic objects, where this would not be the case?

This sort of stuff is specifically addressed by the older paper, although I don't know off hand whether any of it has been superseded. If I understand them correctly, they conclude that it doesn't seem likely that intervening gas clouds would plausibly be moving fast enough to account for some of the known cases, and try to suggest some possible alternatives, but those are not entirely satisfactory.

The thing which puzzled me about the Qin et al paper is effectively summarized in the last paragraph on page 4:

The fact that emission redshifts of quasars are larger than the great majority of their corresponding absorption redshifts obviously contradicts with the work of Arp et al. (see Section 1).

This looks like an error to me; Arp's position is very clearly that quasars have intrinsic redshift which adds to the distance redshift, so if Arp were right one would expect emission redshifts to be even larger than for standard theory.

Overall, I'm having difficult finding the evidence to distinguish between "facts" about quasars derived from observation and "facts" derived from theory assuming black holes, so it's difficult for me to work out any more details of how this idea would change anything. I probably won't have time to look into this any more before I have to resume the "day job" and give up physics until the summer.

 

[Jonathan Scott]

Why quasars have no "intrinsic redshift"

In a phrase, because quasars are merely one kind of AGN (active galactic nucleus).

One of the big advances in quasar research was the formulation of http://www.mssl.ucl.ac.uk/www_astro/agn/agn_unified.html" *. An enormous amount of work has been done confirming (and modifying) this; the net - so far as "quasar intrinsic redshift" is concerned - is that quasars have the same redshifts as galaxies do.

For a great many AGNs, including many quasars, the redshift of both the nucleus and the host galaxy of which it is the nucleus can, and has, been measured; no systematic differences have been reported.

Sorry, I forgot to respond to this last point (because I went on to the next post).

Even by Arp's original observations, "young" quasars (those closest in the sky to the apparent parent galaxy) often have significant intrinsic redshifts, but "old" quasars appear to evolve into galaxies where the surrounding material has the same redshift as the quasar and the redshift is only slightly more than the parent galaxy. This means that although there may be good arguments against intrinsic redshifts, comparison with the host galaxy is not a very strong one.

Note that if black holes do NOT occur, then quasars could be initially ejected from a parent galaxy spinning with relativistic speed, but then gradually lose angular momentum and mass by blowing off or shedding material over time, and hence decrease in intrinsic redshift. (Also, the ejected matter could initially be in an unstable configuration, moving relativistically and hence with a significant velocity redshift).

In contrast, black hole theory does not provide any mechanism for a quasar to lose mass.

 

[Nereid]

I'll start at the end:

Overall, I'm having difficult finding the evidence to distinguish between "facts" about quasars derived from observation and "facts" derived from theory assuming black holes, so it's difficult for me to work out any more details of how this idea would change anything. - JS

It's a good summary; the post (that I'm quoting) is chockablock full of misunderstandings, particularly about astronomy and astrophysics, and unless and until you've taken the time to bring yourself up to speed on the key parts, you're going to keep making bloopers.

As a basic sanity check, I already took the example of PKS 0119-04 from the 1977 paper, which has a delta v of about 0.009c, which I'll round up to 0.01c. This would appear to be trivially achievable by a stable low orbit around a supermassive object, because if black holes did not happen, the object could be large enough that its surface is not far below the orbit and the gravitational potential of the surface is similar to that of the orbit.

Care to show your working?

Remember that the absorbers, in quasar spectra, have some very well-established characteristics, and if your toy model can't reproduce those - to within ~3 OOM say - then whether it's "trivially achievable" is irrelevant.

There are also problems with the emission source, but let's leave those aside for now.

However, magnetic fields and electromagnetic interactions could make the orbit environment more complex than for a black hole.

And even more irrelevant for our purposes ... the footprint of such "magnetic fields and electromagnetic interactions" in the absorption line spectra would be screamingly obvious.

I'm not sure what the basis is here for these suggestions; are you referring to some observed characteristics of specific quasars?

I was trying to get you to go back to the (astronomy) basics, the actual (historical) observations ... if you can't get your head around those, our discussion will be marked by confusion (at best) and I'll lose my patience (and temper, at worst).

Are you willing to take things one step at a time, as I asked? If so, I'm willing to walk you through them ... but from what I've seen in your posts so far, you'll be on a very steep learning curve, and the discussion will takes weeks ...

I'm aware that an apparent accretion disk has been seen (by subtracting unpolarized light) - are you referring to that particular case?

I am unaware of this; do you have any references?

An absorption system which is at a higher redshift would be the innermost cloud or ring. If the central object was not a black hole, I don't think the disk would necessarily be continuous, but would be affected for example by magnetic fields which could cause it to form separate bands. It might not even be particularly stable.

See above; absorption systems, in quasars, have well-established characteristics.

If black holes do not occur, then the quasar is effectively a hyper-massive star (probably spinning very fast, significantly smearing the emission spectrum by doppler effects, although if we are seeing it from above a pole, the smearing could be significantly decreased). It can also have a significant intrinsic redshift, making it closer than it appears. Both of these factors mean that less extreme physics is needed to achieve the required luminosity.

Are these your own ideas? If so, why not write them up and get your paper published?

If not, then please give at least one reference.

My first impression is that what you write is so full of holes that it makes the proverbial swiss cheese look completely solid, but I don't want to come to hasty conclusions.

Let's take a closer look at this Qin et al. paper, shall we?

First, do you understand the point about absorption systems needing to be backlit by emission sources? IOW, in any 'quasar', whatever is causing the absorption lines, it must be in the foreground (between us and the emission source)?

Can you think of any physically plausible circumstances, for extragalactic objects, where this would not be the case?

This sort of stuff is specifically addressed by the older paper, although I don't know off hand whether any of it has been superseded. If I understand them correctly, they conclude that it doesn't seem likely that intervening gas clouds would plausibly be moving fast enough to account for some of the known cases, and try to suggest some possible alternatives, but those are not entirely satisfactory.

Let's have less off hand and more actual science, shall we?

I was starting very, very simply - an absorption system, in an astronomical object, requires an emission source that backlights it; ergo the absorption system must be in the foreground of the emission source.

I was hoping for a simple 'yep, that's a fair place to start' or 'no, here's a plausible scenario under which the emission source would be in the foreground'. Would you be kind enough to try to answer my question, the one I actually asked, again?

The thing which puzzled me about the Qin et al paper is effectively summarized in the last paragraph on page 4:

The fact that emission redshifts of quasars are larger than the great majority of their corresponding absorption redshifts obviously contradicts with the work of Arp et al. (see Section 1).

This looks like an error to me; Arp's position is very clearly that quasars have intrinsic redshift which adds to the distance redshift, so if Arp were right one would expect emission redshifts to be even larger than for standard theory.

It's not an error ... I think I understand the problem you're having: you simply lack a firm enough grasp of the basic astrophysics to be able to comprehend what you're reading (see above).

[...] I probably won't have time to look into this any more before I have to resume the "day job" and give up physics until the summer.

Perhaps it's time, then, to call it a day, and not comment further until you do have the time?

 

[Nereid]

Why quasars have no "intrinsic redshift"

In a phrase, because quasars are merely one kind of AGN (active galactic nucleus).

One of the big advances in quasar research was the formulation of the unified model of AGNs*. An enormous amount of work has been done confirming (and modifying) this; the net - so far as "quasar intrinsic redshift" is concerned - is that quasars have the same redshifts as galaxies do.

For a great many AGNs, including many quasars, the redshift of both the nucleus and the host galaxy of which it is the nucleus can, and has, been measured; no systematic differences have been reported.

Sorry, I forgot to respond to this last point (because I went on to the next post).

Even by Arp's original observations, "young" quasars (those closest in the sky to the apparent parent galaxy) often have significant intrinsic redshifts, but "old" quasars appear to evolve into galaxies where the surrounding material has the same redshift as the quasar and the redshift is only slightly more than the parent galaxy. This means that although there may be good arguments against intrinsic redshifts, comparison with the host galaxy is not a very strong one.

Yet another example of where your lack of knowledge of the field has lead you to a blooper ...

Historically, quasars were point sources in the optical waveband - on photographic plates the image of a quasar is no different from that of a star, hence the name ("quasi-stellar").

Quite quickly, however (~<5 years?), a faint 'fuzz' was detected around the central point source, in plate images of some quasars (later found to be what we today call low-z quasars). Perhaps the bright point source is but the central nucleus of a galaxy, much like the nucleus of normal spiral and elliptical galaxies, the thinking went.

Fast forward ~4 decades; there are now direct images, in the optical and IR wavebands (and perhaps x-ray, UV, and others too) of quasars as the nuclei of galaxies; the galaxies these quasars are in are called the 'host galaxies'.

The redshifts of these hosts are, generally, difficult to measure (not least because the nuclei are so much brighter); however as far back as the 1980s (IIRC) such observations were made (and reported in the literature) ... the nucleus and host galaxy have the same redshift (usual caveats, e.g. about errors, apply).

Now back to the main story.

Do quasars, as AGNs, form a continuum? Or are they, in fact, two or more distinct classes of object that merely appear to the same?

Specifically, to what extent are quasars merely more luminous AGNs than the many examples of the nuclei of galaxies that seem active (but, as galaxies, are otherwise quite ordinary)?

The answer, backed by decades of research and millions of observations (and thousands of papers) is that they are but a single class of object, today called AGNs. The totality includes type 2 quasars, blazars, OVV objects, Seyferts (of type 1 and 2), several kinds of objects classified by their characteristics in the radio wavebands, etc, etc, etc.

You can, I hope, see where this leads ... and why it is fatal to Arp's ideas (and intrinsic redshifts, for quasars, in general).

Oh, and "Arp's original observations" have not stood the test of time, scientifically speaking: all testable hypotheses built on his ideas (that I have seen) have been falsified by actual observations. Note the huge blooper here: the conflating of what you remember about "Arp's original observations" with honest-to-goodness astronomical observations*.

Note that if black holes do NOT occur, then quasars could be initially ejected from a parent galaxy spinning with relativistic speed, but then gradually lose angular momentum and mass by blowing off or shedding material over time, and hence decrease in intrinsic redshift. (Also, the ejected matter could initially be in an unstable configuration, moving relativistically and hence with a significant velocity redshift).

In another forum I am active in (BAUT forum), this is called 'word salad'.

If you want to develop these ideas, please do so, and get a paper published; if not, please stop writing such "Overly Speculative Posts" (to quote from the PF rules).

In contrast, black hole theory does not provide any mechanism for a quasar to lose mass.

You've lost me ... can you clarify please?

* if you ever get around to digging up some of the Arp papers, you'll quickly understand why I call what you wrote a blooper.

 

[Jonathan Scott]

I do not have the time nor the expertise to rewrite the theory of quasars.

I don't have any problem with the idea that quasars and AGNs are just different aspects of the same sort of things. I don't have any problem with the idea that when quasars are surrounded by other material, it is at the same redshift.

If the material around the quasars which Arp would call the "youngest", with significant redshifts relative to their apparent parent, shows signs of actual galaxy material around the quasar, where the stars have the same redshift, that would certainly provide evidence against intrinsic redshift. Have examples of this been found now?

My overall point is simply that if quasars had surfaces rather than being black holes, this might help explain some of their more curious features, and could perhaps even be consistent with Arp's somewhat incredible suggestions about quasars changing with time.

Non-microscopic black holes can never decrease in mass, by standard theory. This means it would require a very contrived mechanism for any material in their vicinity to decrease in redshift with time. In contrast, an ultra-massive body which was not a black hole would have no such restriction.

 

[Nereid]

I do not have the time nor the expertise to rewrite the theory of quasars.

I don't have any problem with the idea that quasars and AGNs are just different aspects of the same sort of things. I don't have any problem with the idea that when quasars are surrounded by other material, it is at the same redshift.

Hold onto that thought ...

If the material around the quasars which Arp would call the "youngest",

So to discuss this in any meaningful way, we need to start with a mutual understanding of what Arp calls (not 'would call') the youngest quasars, don't we?

What are they? As in both specific examples and a reasonably useful (in an operational sense) definition ...

with significant redshifts relative to their apparent parent,

What is an "apparent parent"?

Specifically, how can one (an unbiased, objective scientist) determine which galaxy (or galaxies) of a "youngest" quasar are its "apparent parent(s)"?

More generally, absent clear unambiguous answers to basic definitional questions like this, how can we proceed?

shows signs of actual galaxy material around the quasar, where the stars have the same redshift, that would certainly provide evidence against intrinsic redshift.

Galaxies, of course, are comprised of much more than mere stars ... most (all?) of them have dark matter halos, all but normal ellipticals have lots of gas and dust (and most normal ellipticals also have significant amounts of gas and dust too), and so on.

So may we broaden your test to any or all such components?

Have examples of this been found now?

Making some heroic assumptions about how you might answer the above questions, "yes".

My overall point is simply that if quasars had surfaces rather than being black holes, this might help explain some of their more curious features, and could perhaps even be consistent with Arp's somewhat incredible suggestions about quasars changing with time.

And my overall point, well one of them, is simply that what you write is so confused, so full of muddled thinking, mis-remembered failed ideas, and so on that it's hard to have a coherent discussion.

Let's try this: "if quasars had surfaces rather than being black holes" - did you actually read the material I provided links to re the unified model of AGNs?

"quasars", the astronomical objects which are imaged and otherwise studied by a wide variety of techniques, across wavebands ranging from ~TeV gammas to the radio, are inferred to be complex objects. There is a SMBH (supermassive black hole) at the core, with the observed continuum emission coming from an accretion disk around this*. Then there's a dusty torus (which contains a lot of gas), a pair of polar jets, a broad-line region, and a narrow line region (and more, perhaps).

If you think that "if quasars had surfaces [...] this might help explain some of their more curious features", please develop the idea, write it up as a paper, and get it published in a relevant, peer-reviewed journal. Until then ...

Non-microscopic black holes can never decrease in mass, by standard theory. This means it would require a very contrived mechanism for any material in their vicinity to decrease in redshift with time. In contrast, an ultra-massive body which was not a black hole would have no such restriction.

And this is relevant, how?


* this is, of course, a simplification; for many quasars the jets provide much, or even most, of the observed continuum emission

 

[ray b]

as we know a black hole does not suck in matter
by any magic process, just gravity
how do we account for the huge energy's seen in quasars
how would a close orbiting pair of BHs look for a model of a quasar center ?
would a close orbiting pair of BHs have jets?
would the increase in in falling matter be enuff to account for the energy outputs ?
would a close orbiting pair of BHs have any property's not seen in quasars ?

 

[ray b]

on the metals issue
if we have never seen a pop3 star let alone
one go super nova
how can one say the heavy metal output of such an event?

 

[Nereid]

as we know a black hole does not suck in matter
by any magic process, just gravity
how do we account for the huge energy's seen in quasars

This is a good question!

Rather than try to answer it in a general way, may I ask you, ray b, to say a bit about what level of math, physics, and astrophysics you're comfortable with?

Specifically, have you heard of http://www.daviddarling.info/encyclopedia/A/accretiond.html" (discs)? Do you understand something about the physics of such objects (which are, of course, not limited to quasars)?

how would a close orbiting pair of BHs look for a model of a quasar center ?

Off the top of my head, not much different than just one ... except that they'd lose energy (due to gravitational radiation, among other things) and end up as a single SMBH (an 'inspiral event'). See http://fr.arxiv.org/abs/astro-ph/0109530" for example.

would a close orbiting pair of BHs have jets?
would the increase in in falling matter be enuff to account for the energy outputs ?
would a close orbiting pair of BHs have any property's not seen in quasars ?

See the above link, and the papers which cite it (100, according to ADS).

 

[Jonathan Scott]

Specifically, how can one (an unbiased, objective scientist) determine which galaxy (or galaxies) of a "youngest" quasar are its "apparent parent(s)"?

Arp found various obvious pairings of bright quasars across a specific type of galaxy. I don't know about the exact statistics, but the diagrams of large areas of the skies with only quasars above a certain brightness shown seemed very interesting.

Galaxies, of course, are comprised of much more than mere stars ... most (all?) of them have dark matter halos, all but normal ellipticals have lots of gas and dust (and most normal ellipticals also have significant amounts of gas and dust too), and so on.

So may we broaden your test to any or all such components?

I expect "young" quasars to shed material and interact with surrounding material, but I do not expect them to be surrounded by galaxies. If you broaden the test for example to including general "fuzziness" around a quasar, I will definitely find the results less convincing.

Making some heroic assumptions about how you might answer the above questions, "yes".

I would still be interested to know more about the best evidence available at the moment, if you can give me a specific reference.

"quasars", the astronomical objects which are imaged and otherwise studied by a wide variety of techniques, across wavebands ranging from ~TeV gammas to the radio, are inferred to be complex objects. There is a SMBH (supermassive black hole) at the core, with the observed continuum emission coming from an accretion disk around this*. Then there's a dusty torus (which contains a lot of gas), a pair of polar jets, a broad-line region, and a narrow line region (and more, perhaps).

If the core is NOT an SMBH, this doesn't affect what goes on around it gravitationally outside the surface of the object (by Birkhoff's theorem). It can still for example have an accretion disk and jets. It could have a significant intrinsic magnetic field, which could help explain the jets. It could allow some emission to arise from the surface rather than an accretion disk, and I'd expect the surface radiation to dominate for newly formed quasars, but become less significant for older ones.

My last point was that even one of Arp's most implausible suggestions, that quasar intrinsic redshifts decrease as a new quasar settles down, does not have any simple explanation within black hole theory, but would be easy to explain if quasars did not contain black holes.

If you think that "if quasars had surfaces [...] this might help explain some of their more curious features", please develop the idea, write it up as a paper, and get it published in a relevant, peer-reviewed journal. Until then ...

As far as I know, I'm not inventing this idea, but merely pointing out that a previous idea about quasars which was rejected because of black hole theory might still have some value if black holes do not occur in nature, as suggested by Antoci et al. I don't need to pursue it (and this thread wasn't my idea) but if possible I would like to know whether there is any direct evidence which rules it out (without implicitly relying on black hole theory). If even asking these questions is considered too speculative then I'd be happy to leave it alone.

 

[Nereid]

Specifically, how can one (an unbiased, objective scientist) determine which galaxy (or galaxies) of a "youngest" quasar are its "apparent parent(s)"?

Arp found various obvious pairings of bright quasars across a specific type of galaxy. I don't know about the exact statistics, but the diagrams of large areas of the skies with only quasars above a certain brightness shown seemed very interesting.

If you say so ...

But unless and until you can dig up a reference or three ...

FWIW, from quite early on Arp got a lot of flack, from other astronomers, for his, er, generous interpretations and his, um, less than solid grasp of statistics (and I think it's fair to say I'm being generous). Be that as it may, a re-examination of Arp's "obvious pairings of bright quasars across a specific type of galaxy" looks rather ... interesting ... in light of the published results from good surveys (like http://www.sdss.org/" ).

Earlier I said "put up or shut up"; this is one particularly pertinent case where I think it important for you do so ... if only because your claims rest centrally on this point.

Galaxies, of course, are comprised of much more than mere stars ... most (all?) of them have dark matter halos, all but normal ellipticals have lots of gas and dust (and most normal ellipticals also have significant amounts of gas and dust too), and so on.

So may we broaden your test to any or all such components?

I expect "young" quasars to shed material and interact with surrounding material, but I do not expect them to be surrounded by galaxies. If you broaden the test for example to including general "fuzziness" around a quasar, I will definitely find the results less convincing.

Hmm ...

... so what testable hypothesis are you proposing?

Please re-state it, in as precise - and quantitative - a form as possible.

Making some heroic assumptions about how you might answer the above questions, "yes".

I would still be interested to know more about the best evidence available at the moment, if you can give me a specific reference.

"Best evidence available" ... for what?!?

As I pointed out already, more than once, the nature of the "evidence" depends - vitally - on the hypothesis. And you are being incredibly unforthcoming with the details necessary to actually test any such.

If the core is NOT an SMBH, this doesn't affect what goes on around it gravitationally outside the surface of the object (by Birkhoff's theorem). It can still for example have an accretion disk and jets. It could have a significant intrinsic magnetic field, which could help explain the jets.

Sans anything quantitative, check.

It could allow some emission to arise from the surface rather than an accretion disk, and I'd expect the surface radiation to dominate for newly formed quasars, but become less significant for older ones.

Really?

And:

a) how do you propose analysis of the collective body of observations be performed, to show there is emission from any surface?

b) what "surface radiation" do you expect? Based, presumably, on some non-GR theory or other ... Quantitative, testable (in principle) answers please, not yet more word salad.

My last point was that even one of Arp's most implausible suggestions, that quasar intrinsic redshifts decrease as a new quasar settles down, does not have any simple explanation within black hole theory, but would be easy to explain if quasars did not contain black holes.

And GR cannot explain invisible pink fairies either.

Don't you think it rather important to establish whether Arp's ideas have any legs whatsoever, before charging off with speculative ideas on how to account for them?

Especially as these ideas are not accepted as mainstream in astronomy (for very good reasons).

As far as I know, I'm not inventing this idea, but merely pointing out that a previous idea about quasars which was rejected because of black hole theory might still have some value if black holes do not occur in nature, as suggested by Antoci et al.

Well, no, that's not what you are doing.

You are writing your own summary of what you remember reading in a book (not a paper published in a peer-reviewed paper), and (very likely) slanting that to fit some non-mainstream GR idea you have apparently become enamored with.

I don't need to pursue it (and this thread wasn't my idea)

Indeed.

But who wrote the following, and where?

"It seems that there is overwhelming experimental evidence that at least some quasars must have significant intrinsic redshifts (as Arp has been suggesting for years)."

And who has failed, after many, many requests for references, to cite any "experimental evidence" (much less "overwhelming" evidence)?

but if possible I would like to know whether there is any direct evidence which rules it out (without implicitly relying on black hole theory).

OK, so this is my personal opinion (YMMV): you can't "rule out" something that is as vague, qualitative (word salad), and unsupported by any references to papers published in relevant peer-reviewed journals as what you have written in this thread!

And this is quite apart from what seems to be a sustained effort to shift the "burden of proof".

If even asking these questions is considered too speculative then I'd be happy to leave it alone.

Well, that's for a Mentor to say.

However, I note that your posts seem remarkably free of questions, yet full of unsubstantiated assertions, assertions which you have, for the most part - to date - declined to back with relevant published papers.