Quasar Turn On z<1 Quasar Clustering

[betzalel]

Based on assumptions concerning the quasar mechanism it was assumed that quasars are turned on due to mergers.

Observationally for z<1 where it is possible to determine if the quasar's associated galaxy is or is not merging it has been found that the quasar turn on does not correlate with mergers.

This means from a that mechanism that turns what quasar on is related to something internal to the galaxy or to the quasar.

Supporting that conclusion is the finding that quasars occur more commonly in voids rather than in high dense regions.

Supporting this conclusion is for z<1 mergers are not common.

The above finding makes it difficult to explain why there are clusters of quasars that are anomalies at 6 sigma in z<1.2.


http://arxiv.org/abs/1009.3265v2

THE BULK OF THE BLACK HOLE GROWTH SINCE z ∼ 1 OCCURS IN A SECULAR UNIVERSE:
NO MAJOR MERGER-AGN CONNECTION⋆What is the relevance of major mergers and interactions as triggering mechanisms for active galactic nuclei (AGN) activity? To answer this long-standing question, we analyze 140 XMM-Newton-selected AGN host galaxies and a matched control sample of 1264 inactive galaxies over z ∼ 0.3–1.0 and M∗ < 1011.7M⊙ with high-resolution HST/ACS imaging from the COSMOS field. The visual analysis of their morphologies by 10 independent human classifiers yields a measure of the fraction of distorted morphologies in the AGN and control samples, i.e., quantifying the signature of recent mergers which might potentially be responsible for fueling/triggering the AGN. We find that (1) the vast majority (>85%) of the AGN host galaxies do not show strong distortions, and (2) there is no significant difference in the distortion fractions between active and inactive galaxies. Our findings provide the best direct evidence that, since z ∼ 1, the bulk of black hole (BH) accretion has not been triggered by major galaxy mergers, therefore arguing that the alternative mechanisms, i.e., internal secular processes and minor interactions, are the leading triggers for the episodes of major BH growth. We also exclude an alternative interpretation of our results: a substantial time lag between merging and the observability of the AGN phase could wash out the most significant merging signatures, explaining the lack of enhancement of strong distortions on the AGN hosts. We show that this alternative scenario is unlikely due to: (1) recent major mergers being ruled out for the majority of sources due to the high fraction of disk-hosted AGN, (2) the lack of a significant X-ray signal in merging inactive galaxies as a signature of a potential buried AGN, and (3) the low levels of soft X-ray obscuration for AGN hosted by interacting galaxies, in contrast to model predictions.

http://arxiv.org/abs/0710.1631v1

ACTIVE GALACTIC NUCLEI IN VOID REGIONS
We present a comprehensive study of accretion activity in the most underdense environments in the universe, the voids, based on the SDSS DR2 data. Based on investigations of multiple void regions, we show that Active Galactic Nuclei (AGN) are definitely common in voids, but that their occurrence rate and properties differ from those in walls. AGN are more common in voids than in walls, but only among moderately luminous and massive galaxies (Mr < −20, log M∗/M⊙ < 10.5), and this enhancement is more pronounced for the relatively weak accreting systems (i.e., L[OIII] < 1039 erg s−1). Void AGN hosted by moderately massive and luminous galaxies are accreting at equal or lower rates than their wall counterparts, show lower levels of obscuration than in walls, and similarly aged stellar populations. The very few void AGN in massive bright hosts accrete more strongly, are more obscured, and are associated with younger stellar emission than wall AGN. These trends suggest that the accretion strength is connected to the availability of fuel supply, and that accretion and starformation co-evolve and rely on the same source of fuel.

http://arxiv.org/abs/1108.6221v1

Two close Large Quasar Groups of size approx. 350 Mpc at z = 1.2
What is the relevance of major mergers and interactions as triggering mechanisms for active galactic nuclei (AGN) activity? To answer this long-standing question, we analyze 140 XMM-Newton-selected AGN host galaxies and a matched control sample of 1264 inactive galaxies over z ∼ 0.3–1.0 and M∗ < 1011.7M⊙ with high-resolution HST/ACS imaging from the COSMOS field. The visual analysis of their morphologies by 10 independent human classifiers yields a measure of the fraction of distorted morphologies in the AGN and control samples, i.e., quantifying the signature of recent mergers which might potentially be responsible for fueling/triggering the AGN. We find that (1) the vast majority (>85%) of the AGN host galaxies do not show strong distortions, and (2) there is no significant difference in the distortion fractions between active and inactive galaxies. Our findings provide the best direct evidence that, since z ∼ 1, the bulk of black hole (BH) accretion has not been triggered by major galaxy mergers, therefore arguing that the alternative mechanisms, i.e., internal secular processes and minor interactions, are the leading triggers for the episodes of major BH growth. We also exclude an alternative interpretation of our results: a substantial time lag between merging and the observability of the AGN phase could wash out the most significant merging signatures, explaining the lack of enhancement of strong distortions on the AGN hosts. We show that this alternative scenario is unlikely due to: (1) recent major mergers being ruled out for the majority of sources due to the high fraction of disk-hosted AGN, (2) the lack of a significant X-ray signal in merging inactive galaxies as a signature of a potential buried AGN, and (3) the low levels of soft X-ray obscuration for AGN hosted by interacting galaxies, in contrast to model predictions.

 

[Chronos]

Good to see you back again, Halton.

 

[betzalel]

Some are saying that the discovery of a 4 billion light year group of quasars indicates that something might be fundamentally incorrect with the quasar model and/or with the big bang model (R – W concordance cosmology).

The authors of the 4 billion light year group of quasars paper and the technical summary brief are both missing a very important related quasar theoretical problem, that appears to be a paradox.

The second theoretical problem with the discovery of very, very large quasar structures (see below for a discussion of the first theoretical problem which is the problem of explaining large structures and patterns in the cosmos Vs the uniformity of the CMB). The standard quasar model assumes the quasars' luminosity is caused by gas falling into a super massive black hole. To explain the evolution of quasar density (number of quasars that are turned on at a specific redshift) by redshift (the standard assumption is quasars are distant objects as opposed to the less popular hypothesis that when the quasars turn on the physics of the turn on changes the redshift of the quasar spectrum and the redshift of their host galaxy. There are a couple of hundred published papers concerning the less popular hypothesis, including a number of recent papers by quasar specialists, see comment for details.) quasars must turn on and off as light bulbs running in the on state for no more than 100 million years.

Now why is it a problem that there is an observed group of quasars that stretches 4 billion light years across the universe? There is no reason why a group of active galaxies that stretches 4 billion light years would suddenly all turn on their quasars. What is special about a 4 billion light year region of the universe that would turn on all of the AGN in that region of the universe?

Comment:
There is an interesting set of peculiar and unexplained quasar anomalies that might be related to the finding that there is an apparent 4 billion light year group of quasars. I will re-active the thread that has papers that note there is anomalous quasar luminosity evolution with redshift (quasars gradually get less luminous with redshift and the quasar minimum luminosity gradually gets less with redshift which is anomalous as there is no known mechanism to gradually change the active galaxies with redshift), the observational fact that quasar spectrum variance with time - quasars for some unknown reason pulsate with very long periods, that observation fact might have something to do with the physics of what a quasar is - does not exhibit time dilation with redshift - all other time varying distant objects, super nova for example, exhibit time dilation with redshift (time dilation is a basic general relativity effect due to the expansion of the universe if the quasars are distant objects) and the observational fact that there is no evolution of AGN host gas metallicity with observed quasar spectrum (i.e The most distant quasar spectrum has solar or super solar metallicity in their spectrum which does make sense if they are truly distant objects. Galaxy spectrum metallicity evolves with redshift.)

The large structure in general problem is related to the specific problem of what could turn on the quasars. Everyone agrees that variance analysis of the cosmic microwave background CMB indicates (if the microwave radiation was caused by a big bang explosion 13.7 billion years ago as opposed to a different cause and the big bang did not happen) then the universe was very, very, uniform, 13.7 billion years ago to create the light that has hypothesized to expand to what is now observed as the CMB. The large structure problem is if the energy distribution 13.7 billion years ago was very, very, uniform, one would expect that there should be a very, very uniform distribution of galaxies with redshift.

That is not observed. The universe is very, very, clumpy. And in addition there are these weird unexplained patterns and grouping of galaxies that seems to indicate there is a missing mechanism which creates and explains the patterns.

To explain the observation that the universe is very, very, clumpy rather than very, very, uniform, a theory was added to the big bang theory, this add on theory a theory within a theory is called “inflation”. Inflation is a separate theory. If inflation is theoretically impossible, did not happen, then the current cosmological model is in crisis.

Currently there is no known physical mechanism to cause the first “inflation” or to limit inflation or to make the exact right parts of the early universe to inflate to create the observed super structures and the peculiar lattice of galaxies or to stop inflation from starting again.

The inflation mechanism problem and the anti matter problem are some of the very basic fundamental paradox problems that are not discussed in Cosmology 101 courses. i.e. That the universe began 13.7 billion years ago from a burst of energy that changed to mass with no observable anti matter created.

As cosmological observational analysis is now mature, as compared to say 35 years ago when one hypothesis was selected over the others, there appears to be sufficient observational evidence to solve the cosmological model problem. What is interesting is there are groups of related paradoxes and anomalies which appear to indicate the standard cosmological model is incorrect. It is very rare that a group of researchers have an opportunity to redefine an entire field of science.http://www.sciencedaily.com/releases/2013/01/130111092539.htm

Biggest Structure in Universe: Large Quasar Group Is 4 Billion Light Years Across
Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances. These periods are 'brief' in astrophysics terms but actually last 10-100 million years.
The team, led by Dr Roger Clowes from UCLan's Jeremiah Horrocks Institute, has identified the LQG which is so significant in size it also challenges the Cosmological Principle: the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from.

The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle. The Principle is assumed but has never been demonstrated observationally 'beyond reasonable doubt'.

http://arxiv.org/abs/1211.6256

A structure in the early universe at z ~ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology

A Large Quasar Group (LQG) of particularly large size and high membership has been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume^1/3) ~ 500 Mpc (proper size, present epoch), longest dimension ~ 1240 Mpc, membership of 73 quasars, and mean redshift <z> = 1.27. In terms of both size and membership it is the most extreme LQG found in the DR7QSO catalogue for the redshift range 1.0 <= z <= 1.8 of our current investigation. Its location on the sky is ~ 8.8 deg north (~ 615 Mpc projected) of the Clowes & Campusano LQG at the same redshift, <z> = 1.28, which is itself one of the more extreme examples. Their boundaries approach to within ~ 2 deg (~ 140 Mpc projected). This new, huge LQG appears to be the largest structure currently known in the early universe. Its size suggests incompatibility with the Yadav et al. scale of homogeneity for the concordance cosmology, and thus challenges the assumption of the cosmological principle.