Article quotation:
"The most striking
case corresponds to the old, high-redshift quasar APM
08279+5255 (z = 3.91, t = 2.1 Gyr) (Hasinger et al. 2002;
Friaca et al. 2005), which Standard flat FRW models with
cosmological constant fail to accommodate..."
Could any of you please comment or explain this strange case?
Yes, this is only one of many early massive quasars whose ages are difficult to explain in the young universe represented by their high quasars.
The worst one, so far, (Jan 2015) is SDSS J013127.34–032100.1: a candidate blazar with a 11 billion solar mass black hole at z=5.18 (http://arxiv.org/abs/1501.07269)
From that paper:
(From Abstract)
"This implies that there must be other (hundreds) sources with the same black hole mass of SDSS J013127.34–032100.1, but whose jets are pointing away from Earth."
(From Discussion and Conclusions)
"How can such a large mass be produced at z = 5.18? At this redshift the Universe is 1.1 Gyr old. Fig. 4 shows the change of the black hole mass in time, assuming different efficiencies . If the hole is not spinning, and η< 0.1, then it is possible to grow a black hole up to 11 billion solar masses starting from a 100M⊙ seed if the accretion proceeds at the Eddington rate all the time. But if η = 0.3, appropriate for a maximally spinning and accreting hole (Thorne 1974), then the growth is slower, and an Eddington limited accretion cannot produce a 1.1 × 10^10M⊙ black hole at z = 5, unless the seed is 10^8M⊙ at z = 20.
This poses the problem: jetted sources are believed to be associated with fastly spinning black holes, therefore with highly efficient accretors. If the accretion is Eddington limited, jetted sources should have black holes lighter than radio–quiet quasars with not–spinning holes."
The solution they propose is that if some of the accretion energy went into powering the jet then it did not contribute to the Eddington limitation on the accretion rate.
Still the existence of this 'blazar', and the inference that there must be hundreds more, stretches the envelope limiting how massive an object can be that exists in the early universe.
Note the Eddington limited accretion rate determines the maximum rate that an object can accrete, so the actual rates, and hence the sizes achievable at a set red shift, are going to be less than this limit.
It seems that there is an age problem, or at least tension in the early universe. This tension would be relieved by the linearly expanding model.
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