Quasar Anomalies: Lack of Time Dilation in Variability

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Discussion Overview

The discussion centers on the lack of observed time dilation in the variability of quasars as reported in a study analyzing quasar light curves and their Fourier power spectra. Participants explore the implications of this finding on cosmological theories and the nature of quasars, considering various explanations and challenges to established views.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants express concern over the lack of time dilation in quasar variability, suggesting it poses a serious challenge to modern cosmological theories.
  • One viewpoint suggests that time dilation might not be a property of the Universe, implying a non-expanding Universe, though this contradicts strong support for the big bang theory.
  • Another perspective proposes that quasars may not be at cosmological distances, a claim that has been historically disputed but has gained support from studies of quasar host galaxies.
  • Some argue that observed variations in quasars could be due to intervening processes like gravitational microlensing, while others contend that intrinsic variations from the central accretion disc are more significant.
  • A participant references studies that argue against microlensing as the dominant cause of quasar variability, noting evidence of asymmetric light-curve profiles.
  • Suggestions are made to investigate potential biases in the data analysis, including selection effects related to redshift and quasar color, as well as the intrinsic nature of quasar variability.
  • One participant mentions a related study on gamma-ray bursts that finds evidence of time dilation, suggesting a contrast with quasar findings.
  • Concerns are raised about the reliability of the peer review process in validating the findings of the original study.

Areas of Agreement / Disagreement

Participants do not reach a consensus; multiple competing views and uncertainties remain regarding the implications of the findings and the nature of quasar variability.

Contextual Notes

Limitations include potential biases in the selection of quasar samples, the unknown details of quasar variability, and the unresolved nature of the mechanisms behind observed variations.

  • #61
turbo-1 said:
A naked BH would have a high redshift relative to the neutral gas surrounding it. There is absolutely no requirement for the H to have been expelled from the BH in order to exhibit a difference in redshift. In fact, I envision just the opposite - that a naked BH may be ejected from a galaxy by gravitational slingshot or by radiation recoil, and begin accreting dust and gas from the IGM. Gradually, the infalling dust and gas heats up enough to ionize larger and larger regions around the BH.

A giant black hole cannot be given a slingshot to relativistic velocities, it's just not dynamically possible.
 
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  • #62
RandallB said:
However, I missed the “observed blueshift” involved. Do you know some examples or links that discuss these blueshift observations?
Are blueshifts quantified somehow, like with negative “z” numbers?

Blueshifted relative to the quasar, not our rest frame. In other words, we see the quasar at a very large distance (high redshift). Between us and the quasar is neutral gas that absorbs some of the light from the quasar. Since it's not as far away, this gas will absorb at a wavelength that is blueshifted relative to the quasar frame.
 
  • #63
SpaceTiger said:
Blueshifted relative to the quasar, not our rest frame. In other words, we see the quasar at a very large distance (high redshift). Between us and the quasar is neutral gas that absorbs some of the light from the quasar. Since it's not as far away, this gas will absorb at a wavelength that is blueshifted relative to the quasar frame.
Then we must observe this as missing light spectra it the light we see in our reference frame. Then by adjusting that spectra, back to a reference frame of the quasar must shows a blue shift required with the local gas in the host galaxy in order to match the know gas naturally available to account for the absorption lines we see.

I guess I can see how we can make those observations.

Do you know if there is a correlation to the blue shift related to the “z speeds”?
Like Host z = 3 minis Quasar z = 9 giving something like a blue shift of “-4 or -5” z, or some other measure of blueshift?
 
  • #64
SpaceTiger said:
A giant black hole cannot be given a slingshot to relativistic velocities, it's just not dynamically possible.
Who said that quasars are moving at relativistic velocities? Certainly not me. It's my undersatanding that, depending of the mass of the host galaxy, the ejection velocity may only need to be a few hundred km/s.
 
  • #65
turbo-1 said:
Who said that quasars are moving at relativistic velocities? Certainly not me. It's my undersatanding that, depending of the mass of the host galaxy, the ejection velocity may only need to be a few hundred km/s.

The effective velocity difference between the neutral hydrogen and quasar can be thousands of kilometers per second. I don't know what you're referring to. Do you have a reference?
 
  • #66
turbo-1 said:
A naked BH would have a high redshift relative to the neutral gas surrounding it. There is absolutely no requirement for the H to have been expelled from the BH in order to exhibit a difference in redshift. In fact, I envision just the opposite - that a naked BH may be ejected from a galaxy by gravitational slingshot or by radiation recoil, and begin accreting dust and gas from the IGM. Gradually, the infalling dust and gas heats up enough to ionize larger and larger regions around the BH.
Leaving aside how the 'naked BH' got to be alone in the IGM, no matter how it accreted anything (baryonic), there's no way we, here on Earth, could observe the accreting gas as having a redshift that had a gravitational component (except, perhaps, if we could watch a 'blob' falling in, and could resolve very broad lines) - the EM from any such accreting gas would be detectable, but if it were close enough to the BH that it had even a quite modest gravitational redshift, we couldn't measure that redshift (the lines would be broadened too much).
 
  • #67
Garth said:
Second - Hawkins has published other papers on his favourite explanation for the phenomenom - http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1996MNRAS.278..787H&data_type=PDF_HIGH&type=PRINTER&filetype=.pdf he argued that this effect, along with a number of other properties of the light curves, are best explained by gravitational microlensing of the quasar continuum region. A population of Jupiter sized primordial BHs with a total density contribution of \Omega_{BHs} = 0.1, (i.e. not baryonic matter) is responsible.
but you still have the problem that the further away the quasar the faster it must blink otherwise you would end up with time dilation effects - and one doesn't.

Not such an outlandish suggestion after all!

In which case you have to explain why distant SN and (apparently) long GRBs do exhibit time dilation.

Garth
No, they do not exhibit time dilation - the light curves are 'stretched'. Time dilation is a possible explanation of this. In any case, have you seen the errors in this? A static universe was 'disproved' but only at the 3 sigma level!
 
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  • #68
ratfink said:
No, they do not exhibit time dilation - the light curves are 'stretched'. Time dilation is a possible explanation of this. In any case, have you seen the errors in this? A static universe was 'disproved' but only at the 3 sigma level!

I'm just dying to hear your theory for the CMB.
 
  • #69
You will have to wait - off topic (BTW did the latest WMAP stuff confirm the axis of evil?)
 
  • #70
ratfink said:
You will have to wait

That was sarcasm. If you have a personal theory, it belongs in IR.


off topic (BTW did the latest WMAP stuff confirm the axis of evil?)

It's not as significant as before, but it's still there. The WMAP team feels that the arguments concerning the "axis of evil" are too a posteriori to be of much use. That's always been my feeling as well. If you want to discuss it, please feel free to bring it up in the WMAP thread.
 
  • #71
ratfink said:
but you still have the problem that the further away the quasar the faster it must blink otherwise you would end up with time dilation effects - and one doesn't.
As has already been pointed out to you, your analysis here is far too simplistic - quasars have several components (which contribute to the observed light), and quasars evolve.

Or perhaps I've misunderstood - do you have a study which you can provide a link to which shows that no 4-component model of quasars can possibly reproduce the observed (Hawkins) power spectra? Or you've done this (quantitative) work yourself, and are considering submitting it to ApJ (or PF's IR section)?

If you've got nothing better than this simplistic handwaving, please stop posting such.
No, they do not exhibit time dilation - the light curves are 'stretched'. Time dilation is a possible explanation of this. In any case, have you seen the errors in this? A static universe was 'disproved' but only at the 3 sigma level!
And your references for this are (I assume they are papers published in peer-reviewed journals)?
 
  • #72
ratfink said:
but you still have the problem that the further away the quasar the faster it must blink otherwise you would end up with time dilation effects - and one doesn't.
Hawkins explanation is that the 'blinking' isn't too far away after all, the variability is actually caused by 'local' Jupiter sized primordial black holes microlensing a more or less constant output from a much more distant quasar.
No, they do not exhibit time dilation - the light curves are 'stretched'. Time dilation is a possible explanation of this. In any case, have you seen the errors in this? A static universe was 'disproved' but only at the 3 sigma level!
See my posts and SpaceTiger's responses from post #29 on the Self Creation Cosmology thread.

Garth
 
  • #73
I agree with Nereid's 'handwaving' characterization. Aside from your confusion between Hawkin and Hawking assertions, let's take another look at the 'axis of evil' thing:

CMB multipole measurements in the presence of foregrounds
http://www.arxiv.org/abs/astro-ph/0603369
Authors: Angelica de Oliveira-Costa (MIT), Max Tegmark (MIT)
. . . Applying our method to the WMAP quadrupole and octopole, we find that their previously reported "axis of evil" alignment appears to be rather robust to Galactic cut and foreground contamination."

How is Nereid 'clearly in error' with her evolutionary explanation? You pointed out nothing aside from unsupported assertions.
 
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  • #74
ratfink said:
To reproduce the Hawking results with evolution one has to assume that all quasars were produced in the Big Bang itself – otherwise you wouldn’t get this ‘nice’ relationship with the greater the redshift the older the quasar. If quasars were to be formed after this point and at different eras, some of the older ones could have larger redshifts than the younger ones and hence ruin the Hawkins result. The assumption you make is not valid.
All you have to do, to get started, is develop some kind of model of how each component changes as it ages, turn the handle, and out pops a predicted relationship (which you can then compare with Hawkins, or anyone else's, observations).

This work doesn't have to assume anything about the origin of quasars, just that they evolve.

I don't see how your input assumption about quasars popping into existence "ruins the Hawkins result" - the observations are what they are.
No problem. http://xxx.lanl.gov/abs/astro-ph/9707260"
Thanks.

I note that that paper was written in 1997, almost the dark ages for high-z SNe studies, and that Adam Riess himself is an author of at least a dozen papers on this topic since then.
 
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  • #75
Restoring a post by ratfink, accidentally deleted

[Moderator note: this is the original post. It should appear between #72 (03-18-2006, 09:39 PM) and #73 (03-19-2006 07:33 AM). I accidentally deleted it, while trying to move an extract to the Feedback section. The extract can be found https://www.physicsforums.com/showthread.php?t=114813". My apologies to ratfink for the error.]
ratfink said:
Nereid said:
As has already been pointed out to you, your analysis here is far too simplistic - quasars have several components (which contribute to the observed light), and quasars evolve.

Or perhaps I've misunderstood - do you have a study which you can provide a link to which shows that no 4-component model of quasars can possibly reproduce the observed (Hawkins) power spectra? Or you've done this (quantitative) work yourself, and are considering submitting it to ApJ (or PF's IR section)?

If you've got nothing better than this simplistic handwaving, please stop posting such.And your references for this are (I assume they are papers published in peer-reviewed journals)?
As has already been pointed out to you, your analysis here is far too simplistic - quasars have several components (which contribute to the observed light), and quasars evolve.

Or perhaps I've misunderstood - do you have a study which you can provide a link to which shows that no 4-component model of quasars can possibly reproduce the observed (Hawkins) power spectra? Or you've done this (quantitative) work yourself, and are considering submitting it to ApJ (or PF's IR section)?
To reproduce the Hawking results with evolution one has to assume that all quasars were produced in the Big Bang itself – otherwise you wouldn’t get this ‘nice’ relationship with the greater the redshift the older the quasar. If quasars were to be formed after this point and at different eras, some of the older ones could have larger redshifts than the younger ones and hence ruin the Hawkins result. The assumption you make is not valid.
If you've got nothing better than this simplistic handwaving, please stop posting such.And your references for this are (I assume they are papers published in peer-reviewed journals)?
No problem. http://xxx.lanl.gov/abs/astro-ph/9707260"
N 1996bj aged 3.35 +/- 3.2 days, consistent with the 6.38 days of aging expected in an expanding Universe and inconsistent with no time dilation at the 96.4 % confidence level
If you don’t mind me saying so, we seem to have a problem here Nereid. We have a conflict of interest on your part. As a participator in the discussion you are clearly in error with your evolution explanation. However when this is pointed out, instead of accepting this you seem to be using the power of your position to ask me to stop posting.
This is something the board administrators need to address. Should a person taking part in a discussion be allowed to moderate it as well?
 
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  • #76
Make your point, ratfink. I'm not a moderator, so the strawman you flung at Nereid is a mere ghost to me. I'm not a big fan of quasar evolution as an explanation of the periodicity anomaly, but, do you have clear, cogent and convincing evidence that rules it out? Citations to peer reviewed papers would be a good place to start.
 
  • #77
Chronos said:
Make your point, ratfink. I'm not a moderator, so the strawman you flung at Nereid is a mere ghost to me. I'm not a big fan of quasar evolution as an explanation of the periodicity anomaly, but, do you have clear, cogent and convincing evidence that rules it out? Citations to peer reviewed papers would be a good place to start.
Very kind of you to request my views on this matter. However, I thought this thread was now as dead as a dodo for the following reasons:

We agreed that the hawkins results were correct (least that is what was said when I asked if anyone had repeated them to show if they were wrong).

Hawkins, in his paper suggested that the variations might well be due to the nearby lensing galaxy i.e. the light from quasars was constant but the lensing galaxies produced the variation and hence no time delay.

No doubt this was included as a sop to the BB contingent just to get the paper published.

It cannot be this because these quasar light curves can be used to determine the Hubble constant, H. Biggs/Briggs? at Joderal bank does this all the time. One looks at two lensed images, determine the delay in the light curves and, hey presto, one can find H - and get it correct. So, no. The variation in the light curves must be due to the quasar itself.

Quasar evolution is out as it would require more distant quasars to 'blink' at a faster rate than younger, nearby ones - so that with the effects of time dilation they would all 'blink' at the same rate here on earth. This is nonsense. I will readily admit that I have not got my head round what it actually means but it requires a relation between redshift, z and the birthdays of the quasars themselves. No way.

So what are we left with?

My conclusion is that the results show that the universe is not expanding and we should not be debating the problem of quasar non time dilation, but the problem of why are supernovae light curves stretched?

However, I don't want to be banned. I have been instructed that i can only respond to the problem of quasar light curves with main stream ideas - and main stream ideas can only say that main stream is wrong.

I put forward a way out to mainstreamers. Regarding the 'quasar inside a galaxy' debate, the quasar mainstream says it is 'behind' a galaxy but others say is 'inside a galaxy. I suggested that it could be explained by looking to see if the quasar is lensed. Mainstream says it should be, others say it should not. I was shouted down on this by main streamers who came up with excuses as to why mainstream science could not explain mainstream ideas.

So you see Chronus, the thread is dead.

I am into 'fingers of God' now so if that appears as a thread I will return. Until then (or something else that interests me) thanks.
 
  • #78
So the universe is not expanding? Or the expansion is not accelerating?

What is so interesting about "fingers of god"? Galaxies in clusters are expected to have velocities distributed in a random manner about the redshift of the cluster, hence the velocities tend to be smeared out in a radial direction.
 
  • #79
ratfink, your views do matter. That is the reason we are all here. I only object to leaping to conclusions. Assuming that particular shred of evidence means the universe is not expanding is unsound, IMO. There are an overwhelming number of other observations that insist it is expanding. But, the few, the proud, and downright confusing observations to the contrary deserve examination. You never know. One odd observation could turn the tables. I'm just not convinced this is it. I would hate to latch on to this issue only to find out it was due to dust on the lens.
 

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