An Old quasar in a Young Universe?

  • Thread starter Garth
  • Start date
Garth
Science Advisor
Gold Member
3,572
105

Main Question or Discussion Point

An Old quasar in a Young Universe?
On the arXiv today:Age of High Redshift Objects - a Litmus Test for the Dark Energy Models The Abstract:
The discovery of the quasar, the APM 08279+5255 at z = 3.91 whose age is 2.1 Gyr has once again led to “age crisis”. The noticeable fact about this object is that it cannot be accommodated in a universe with Omega_m = 0.27, currently accepted value of matter density parameter and w = constant. In this work, we explore the concordance of various dark energy parameterizations (w(z) models) with the age estimates of the old high redshift objects. It is alarming to note that the quasar cannot be accommodated in any dark energy model even for Omega_m = 0.23, which corresponds to 1 sigma deviation below the best fit value provided by WMAP. There is a need to look for alternative cosmologies or some other dark energy parameterizations which allow the existence of the high redshift objects.
(Italics mine)
Just for the record, in the SCC scenario, in the Einstein conformal frame with constant atomic proper masses, the age of the universe at z = 3.91 is 2.8 Gyrs. The authors quote their eprint Cosmological Constraints on a Power Law Universe . Abstract.
Linearly coasting cosmology is comfortably concordant with a host of cosmological observations. It is surprisingly an excellent fit to SNe Ia observations and constraints arising from age of old quasars. In this article we highlight the overall viability of an open linear coasting cosmological model.The model is consistent with the latest SNe Ia ``gold'' sample and accommodates a very old high-redshift quasar, which the standard cold-dark model fails to do.
Here we go again?

Garth
 
Last edited:

Answers and Replies

turbo
Gold Member
3,028
45
Garth said:
Here we go again?

Garth
If we believe that redshift is caused by cosmological expansion, we will continually run into these problems. Many decades ago, it was firmly established that Sirius B had an intrinsic redshift due to its density and strong gravitational field. This is a dwarf star, boys and girls! Quasars are often said by standard model adherents to be powered by black holes with a billion times as much mass, yet these same people deride Arp, the Burbidges, and others who say that quasars can have intrinsic redshift. Where's the logic? Quasars are not as distant, as massive, as energetic, or as old as is commonly believed.
 
Garth
Science Advisor
Gold Member
3,572
105
The age problem is not that severe, and the error bars on the observed quasars age determination have not been published. These are crucial in determining whether the standard model has a problem.
Quasars do have gravitational red shift on top of their cosmological red shift, however if all the red shift was a local gravitational effect then
i. It would be smeared out and
ii. it would not be 'contaminated' by the Lyman Alpha forests that lie between the quasar and us.

Garth
 
SpaceTiger
Staff Emeritus
Science Advisor
Gold Member
2,931
2
For anyone interested in a reasonable analysis of this system, see Hasinger, Schartel, and Komossa 2002. You'll note that they're not fool enough to try to disprove the cosmological model based on that one measurement (which makes a lot of assumptions). In fact, the last sentence of their paper says:

In the near future, Fe abundance measurements of larger samples of high-z QSOs may provide another valuable path to measure cosmological parameters (Hamann & Ferland 1993).
Perhaps we should have a thread reviewing why it's important to have large samples when performing this kind of measurement...
 
Garth
Science Advisor
Gold Member
3,572
105
SpaceTiger said:
For anyone interested in a reasonable analysis of this system, see Hasinger, Schartel, and Komossa 2002. You'll note that they're not fool enough to try to disprove the cosmological model based on that one measurement (which makes a lot of assumptions). In fact, the last sentence of their paper says:
In the near future, Fe abundance measurements of larger samples of high-z QSOs may provide another valuable path to measure cosmological parameters (Hamann & Ferland 1993).
Perhaps we should have a thread reviewing why it's important to have large samples when performing this kind of measurement...
Well if there was just one example that was precisely determined to have an age older than the model universe at the time, would that not present a falsification of the model? Of course the more the merrier....

I found it puzzling that that paper (thank you for the link I had missed that one so far) adopts
Throughout this paper we use a Hubble constant of 50 km s−1 Mpc−1 and a deceleration parameter q0 = 0.5.
a little passe for 2002??

That E-dS universe only gave an age of 1 Gyr at z = 3.91, whereas including DE to accelerate the universe, (yes, DE 'acceleration' is significant even in the early deceleration epoch when the LCDM ages are considerably more than the E-dS equivalent) yields an age of around 1.6 Gyr. Still not enough for the 2.1 Gyr originally reported, but more than Hasinger, Schartel, and Komossa report for "an expected delay of ~1 Gyr until Fe/O reaches solar value". The crucial question is: “How robust is the quoted 2.1 Gyr age for the quasar APM 08279+5255?”

Garth
 
SpaceTiger
Staff Emeritus
Science Advisor
Gold Member
2,931
2
Garth said:
Well if there was just one example that was precisely determined to have an age older than the model universe at the time, would that not present a falsification of the model?
Do you understand how the Fe/O determination of age works? Do you really think that qualifies as a "precise" measurement? We have no "precise" ways of measuring the ages of distant quasars or galaxies.


a little passe for 2002??
If your only claim about cosmological models is:

Given that we find strong indications of a supersolar Fe/O abundance, we are beginning to constrain cosmological models, favoring those that predict larger galaxy ages at a given z.
then it doesn't matter all that much which model you assume in your analysis.

Overall, I think this measurement is really uninteresting, mainly because there are so many possible sources of error. Given that the original observers were unwilling to make any strong statements about cosmology based on their measurements, it was, at best, reckless of Jain & Dev 2005 to claim the following based on them:

There is a need to look for alternative cosmologies or some other dark energy parameterizations which allow the existence of the high redshift objects.
That on top of the fact that they performed their entire analysis without once considering the observational errors makes me hope that this does not make it past the referees.
 
Garth
Science Advisor
Gold Member
3,572
105
SpaceTiger said:
Do you understand how the Fe/O determination of age works? Do you really think that qualifies as a "precise" measurement? We have no "precise" ways of measuring the ages of distant quasars or galaxies.
That wasn't an answer to my question, however, of course I realise that this measurement is not precise, as I posted in #3 above,
The age problem is not that severe, and the error bars on the observed quasars age determination have not been published. These are crucial in determining whether the standard model has a problem.
So the question is how big are those error bars? The fact that Jain and Dev do not quote them, or give a reference for their age of 2.1 Gyrs is very unsatisfactory and I agree with you that the paper is uncomplete and should not pass peer review without it - I would not let it go as it is.

However given that they felt able to publish on the arXiv led me to raise this as a question to be discussed in this thread - others may have references to this age even if I do not.
Spacetiger said:
then it doesn't matter all that much which model you assume in your analysis.
A lot of cosmological parameters are dependent on h or h2. If you take a value h=0.5 when it is generally accepted that it is h=0.71 then h2 is going to be only half its accepted value and, other things being equal, cosmological ages are going to be twice their 'real' value. I just was surprised they took this value of h and wondered why.


Garth
 
SpaceTiger
Staff Emeritus
Science Advisor
Gold Member
2,931
2
Garth said:
That wasn't an answer to my question
Of course a "precise" measurement of an age that was discordant with LCDM would be a falsification. That should go without saying, but in practice, precise measurements are extremely hard to come by.


A lot of cosmological parameters are dependent on h or h2. If you take a value h=0.5 when it is generally accepted that it is h=0.71 then h2 is going to be only half its accepted value and, other things being equal, cosmological ages are going to be twice their 'real' value. I just was surprised they took this value of h and wondered why.
I dunno, it's a good question. The point of my referencing that paper was only to demonstrate the uncertainty of the age measurement. I'm not concerned about their choice of cosmology because they made no bold claims about it.

What I would find interesting is an analysis of a large sample of quasars using this method. If, upon doing this, they still found discordant ages, then it would imply something interesting was going on, either in the cosmology, the star formation history, or our understanding of supernovae at high redshift.
 
Chronos
Science Advisor
Gold Member
11,398
738
I read the paper and found no serious challenges to mainstream models, nor did the authors, so far as I saw. I did see additional constraints on other models.
 
Garth
Science Advisor
Gold Member
3,572
105
Chronos said:
I read the paper and found no serious challenges to mainstream models, nor did the authors, so far as I saw. I did see additional constraints on other models.
Which paper are you referring to?
Certainly that is true with SpaceTiger's link Hasinger, Schartel, and Komossa 2002.
However, my link in the OP was to the eprint by Jain and Dev, in which they say
It is alarming to note that the quasar cannot be accommodated in any dark energy model even for Omega_m = 0.23, which corresponds to 1 sigma deviation below the best fit value provided by WMAP.
Then there certainly is a challenge to the mainstream model, even when the parameters are pushed to their acceptable limits.

The question of whether the eprint poses a serious challenge depends on how robust their quasar age of 2.1 Gyrs. is; that is what are the error bars of their estimation. If they are only +/- 0.1 Gyr. then the mainstream model is in trouble, if they are =/- 0.5 Gyr then it is not. The age of the universe at z = 3.91 with Omega_m = 0.23 and Omega_vac = 0.78 being 1.75 Gyr. (Ned Wright's calculator).

Garth
 
Last edited:
Garth
Science Advisor
Gold Member
3,572
105
Okay, the problem has just deepened! Searching for papers on quasar APM 08279+5255 I find: Cosmological implications of APM 08279+5255, an old quasar at z= 3.91 Alcaniz J.S.; Lima J.A.S.; Cunha J.V, Monthly Notices of the Royal Astronomical Society, Volume 340, Number 4, April 2003, pp. L39-L42(1)
The existence of old high-redshift objects provides an important tool for constraining the expanding age of the Universe and the formation epoch of the first objects. In a recent paper, Hasinger, Schartel & Komossa reported the discovery of the quasar APM 08279 + 5255 at redshift z= 3.91 with an extremely high iron abundance, and estimated age of 2–3 Gyr. By assuming the lower limit for this age estimate and the latest measurements of the Hubble parameter as given by the HST key project, we study some cosmological implications from the existence of this object. In particular, we derive new limits on the dark matter and vacuum energy contribution. Our analysis is also extended to quintessence scenarios in which the dark energy is parametrized by a smooth component with an equation of state px= x x (-1 x < 0) . For flat models with a relic cosmological constant we show that the vacuum energy density parameter is constrained to be 0.78 , a result that is marginally compatible with recent observations from type Ia supernovae (SNe Ia) and cosmic microwave background (CMB). For quintessence scenarios the same analysis restricts the cosmic parameter to x -0.22 . Limits on a possible first epoch of quasar formation are also briefly discussed. The existence of this object pushes the formation era back to extremely high redshifts.
(emphasis mine)

So it looks as if Jain and Dev we quoting the lower end of that age range, with a possible error of -0.1 Gyr. Is not the standard model looking shaky?
Garth
 
Last edited:
Garth
Science Advisor
Gold Member
3,572
105
And again here
Dr Norbert Schartel
European Space Agency
Spain
Tel: 34 91 8131 184
Fax: 34 91 8131 139
E-mail: norbert.schartelesa.int

Dr Fred Jansen
European Space Agency
The Netherlands
Tel: +31 71 565 4426
E-mail: fred.jansenesa.int

Prof. Guenther Hasinger
Max-Planck-Institut f|r extraterrestrische Physik
Germany
Tel: +49 89 30000 3402
Fax: +49 89 30000 3569
E-mail: ghasingermpe.mpg.de

The Solar System formed just 5 thousand million years ago, so it should contain more iron than the quasar, which formed over 13.5 thousand million years ago. The fact that the quasar contains three times more iron than the Sun is therefore a major puzzle.

One possible explanation is that something is wrong with the way astronomers measure the age of objects in the Universe. The almost-holy red shift-distance-age conversion would therefore be wrong. Fred Jansen, ESA's project scientist for XMM-Newton, explains that this would mean rewriting the textbooks. "If you study the evolution of the Universe, one of the basic rules is that we can tie redshift to age. One distinct possibility to explain these observations is that, at the redshift we are looking at, the Universe is older than we think."
(emphasis mine)
They give an alternative explanation for the high Iron content:
If the older-Universe interpretation is wrong, there is only one other, stranger possibility, according to Jansen. Somewhere in the early Universe there must be undiscovered 'iron factories', producing the metal by unknown physical means. Understandably, Jansen is cautious about this, saying, "This is the less likely solution in my opinion."
But at least that idea (if there is no laboratory physics to verify it) would make another good 'epicycle' don't you think?

So, how far are we from falsification of the mainstream model?

Just a thought, Garth.
 
Last edited:
Garth
Science Advisor
Gold Member
3,572
105
Have a look at quasar APM 08279+5255 spectrum:here showing the Iron K edge absorbed by the massive amount (3 x solar) of iron in the outflowing clouds from the quasar at z = 3.91.

Garth
 
Last edited:
SpaceTiger
Staff Emeritus
Science Advisor
Gold Member
2,931
2
Garth said:
So, how far are we from falsification of the mainstream model?
Show me a statistical prevalence of this effect in a larger sample of quasars and I'll be interested. One quasar with an unusual chemical composition just doesn't cut it.
 
Garth
Science Advisor
Gold Member
3,572
105
SpaceTiger said:
Show me a statistical prevalence of this effect in a larger sample of quasars and I'll be interested.
[URL [Broken]
] The First XMM-Newton spectrum of a high redshift quasar - PKS 0537 [/URL],
z = 3.104, (Oct 2000).
However, there is evidence for weak Compton reflection. A redshifted iron K line, observed at 1.5 keV - corresponding to ~6.15 keV in the quasar rest frame - is detected at 95% confidence. If confirmed, this is the most distant iron K line known.
http://www.sron.nl/saxsymp/papers/vignali.ps [Broken]
z > 4, (2004)
The X-ray spectrum of PDS 456 is characterized by a prominent ionized Fe K edge (clearly visible in the data-to-model residuals shown in Fig. 1, panel (a), when a single power-law t is adopted); the edge corresponds to Fe xxiv-xxvi at ~ 8.8 keV .............

Due to the extremely low background in typical Chandra snapshot (~ 4-10 ks) observations, it has also been possible to derive average spectral constraints for subsamples of high-redshift quasars using joint spectral tting with ~ 120-340 X-ray counts [22,23]. At z > 4, optically selected RQQs have a photon index of ~ 1.8-2.0, similar to the results found at low and intermediate redshifts (e.g., [12]). Furthermore, no spectral evolution of the X-ray continuum shape over cosmic time has been found (see [23] and Fig. 4). At high redshift, this result has been supported recently by direct X-ray spectroscopy of QSO 0000 263 at z = 4:10 with XMM-Newton [33].
(Emphasis mine)
Although the ages of these quasars at those high red shifts have not been determined, or at least published, they do have substantial iron abundance at an early cosmological age, therefore it does seem that there may indeed be a “statistical prevalence of this effect”.

SpaceTiger, are you interested?

Garth
 
Last edited by a moderator:

Related Threads for: An Old quasar in a Young Universe?

  • Last Post
2
Replies
49
Views
8K
Replies
2
Views
757
  • Last Post
Replies
3
Views
887
  • Last Post
Replies
4
Views
3K
  • Last Post
Replies
2
Views
570
  • Last Post
Replies
2
Views
3K
Replies
1
Views
423
Replies
11
Views
3K
Top