Extremely large Black Hole discovered 900M years after BB

[Tanelorn]

Whereas SDSS J0100+2802 (the subject of this thread) is one of the most luminous the paper An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30 states (emphasis mine)

So a bit more than "one, or a few".

Garth

What I meant was, this one was quite a bit larger than the rest. i.e, 12 Billion solar masses. (see plot here. not log scale)
http://www.washingtonpost.com/news/...cient-black-hole-the-size-of-12-billion-suns/

Interesting, this quasar has a redshift over 7.1 making it even more difficult to explain, observed at 770 million years after thee BB with 2 billion solar masses.
http://en.wikipedia.org/wiki/ULAS_J1120+0641This group of quasars challenges Einstein's homogeneous requirements:
http://news.discovery.com/space/galaxies/scientists-find-universes-largest-structure-130111.htmA very interesting alignment of spin axes (see video)
http://en.wikipedia.org/wiki/Quasar

Largest ever quasar:
http://www.popsci.com/science/artic...gest-quasar-ever-near-supermassive-black-hole

 

[Garth]

Thank you Tanelorn,

That ULASJ1120+0641 has a luminosity of 6.3×10¹³L_⊙ and hosts a black hole with a mass of 2×10⁹M_⊙ at z=7.085, is beyond the Eddington Limit.

The only way to get this big, and still be bright is with a combination of formation routes

You need a SMBH very early and the only way to get that is with either a direct collapse of baryonic matter into a DM potential well, or a merger of many IMBHs at say z~10 (cosmic age 480Myrs), together with a later (z~8ish cosmic age 650Myrs) accretion of stars, matter etc. forming a bright accretion disc that gives the observed lumninosity.
The problem with this as I see it is that the SMBH mass is so large that its Event Horizon tidal forces are so small that they would swallow up the said stars without forming an accretion disc.

So, unless others can enlighten me, it does seem that we do have an age problem here in the early universe - the universe is younger at this red shift than this object within it.

Garth

 

[wabbit]

Interesting - so how big is the discrepancy? Say, would it be enough to revise the age of the universe by say 200My for the formation process to fall within reasonably expected behaviour, or would it need to be more substantial?

 

[Garth]

There may not be an age-problem after all (although it is close!) Several papers talk about Super Eddington accretion.

SUPER-CRITICAL GROWTH OF MASSIVE BLACK HOLES FROM STELLAR-MASS SEEDS

We consider super-critical accretion with angular momentum onto stellar-mass black holes as a possible mechanism for growing billion-solar-mass black holes from light seeds at early times. We use the radiatively inefficient "slim disk" solution—advective, optically thick flows that generalize the standard geometrically thin disk model—to show how mildly super-Eddington intermittent accretion may significantly ease the problem of assembling the first massive black holes when the universe was less than 0.8 Gyr old. Because of the low radiative efficiencies of slim disks around non-rotating as well as rapidly rotating black holes, the mass e-folding timescale in this regime is nearly independent of the spin parameter. The conditions that may lead to super-critical growth in the early universe are briefly discussed.

X-rays from the redshift 7.1 quasar ULAS J1120+0641.

Super-Eddington accretion would help to reduce the discrepancy between the age of the quasar implied by the small size of the ionized near-zone in which it sits (<10⁷ yr) and the characteristic e-folding time (2.5 × 10⁷ yr if L/LEdd = 2). Such super-Eddington accretion would also alleviate the challenging constraints on the seed black hole mass provided that the quasar has been rapidly accreting throughout its history. The remnant of an individual Population III star is a plausible progenitor if an average L/LEdd > 1.46 has been maintained over the quasar's lifetime.

If a insurmountable age-problem should arise then as I have indicated in my post #6 above a solution might be a modification of a(t) by the presence of another form of DE in the early universe. As we have already added DE to the later universe to make the distant SNe 1a fit, this shouldn't require too great a stretch of the imagination!

For example if we had linear expansion, a(t) = t, then the age at z=7 would be ~2Gyrs and not 770Myrs, more than double the time to 'make things'.

Garth

 

[wabbit]

Thanks ! Indeed I understand if there is an age problem presumably it would be resolved by some changes/tweaks in the model, maybe in the inflation etc... a few 100Mys doesn't sound like that much (I imagine >>1bn years might be another challenge)

 

[wolram]

to show how mildly super-Eddington intermittent accretion may significantly ease the

a lot of things may be.

 

[zoki85]

Let somebody calculate the Schwarzschild radius of it (I'm too lazy)
Here is the formula:

 

[Tanelorn]

List of most distant red shifted events:
http://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects

 

[Garth]

Let somebody calculate the Schwarzschild radius of it (I'm too lazy)
Here is the formula:

The Schwarzschild radius is linearly proportional to M.

The Solar Schwarzschild radius is 2.95 km, so call it roughly 3 km - a 10¹⁰ M_⊙ BH has a Schwarzschild radius of 3x10¹⁰ km.

Garth

 

[wabbit]

a 10¹⁰ M_⊙ BH has a Schwarzschild radius of 3x10¹⁰ km.

So, 200 AU. Respectable.

 

[Tanelorn]

Isn't that bigger than the super massive black hole at the center of the milky way over 12B years later?

These are Radii:

http://en.wikipedia.org/w/index.php?title=Saggitarius_A*_(SMBH)&action=edit&redlink=1 1.27×10^10 meters
http://en.wikipedia.org/w/index.php?title=Andromeda_(SMBH)&action=edit&redlink=1 4.68×10^11 meters
http://en.wikipedia.org/w/index.php?title=NGC_4889_(SMBH)&action=edit&redlink=1 6.2×10^13 meters !http://en.wikipedia.org/wiki/Schwarzschild_radius

Aside: The observable universe's mass has a Schwarzschild radius of approximately 13.7 billion light years!

 

[mfb]

Does the universe expand at the speed of light and speed of gravity?
If yes, then we would have never seen those black holes.
Those black hole are therefore, within our horizon and still growing.
You should be able to see even bigger black hole that are closer to the present time.

Speed is a bad measurement of expansion, because this speed depends on the distance of the object, and there are multiple ways to define "speed" for large distances.
The light emitted there 900 million years needed about 13 billion years to reach us. The light emitted there 1 year later will need 7.3 years more. So we can follow its evolution, but to see how it evolves over millions years we would have to watch for many millions of years. For very long timescales, we cannot neglect the accelerated expansion of the universe any more - this factor of 7.3 will increase more and more, to a point where the quasar redshifts into oblivion. Assuming nothing dramatic changes the future evolution of the universe, we will never see how the black hole looks like today.

 

[Garth]

Isn't that bigger than the super massive black hole at the center of the milky way over 12B years later?

Yes - the Milky Way's BH Sagittarius A has a mass of 4.5x10⁶M_⊙ I was working out the Schwarzschild radius of a 10¹⁰M_⊙ BH.

The Milky Way's SMBH is quite small as far as SMBH's are concerned, and it is also rather quiet - which is probably a good thing for us fragile biological beings here on Earth!

Aside: The observable universe's mass has a Schwarzschild radius of approximately 13.7 billion light years!

That's because the universe is flat - or nearly so - and its average density is the critical density.

Garth

 

[Jorrie]

http://en.wikipedia.org/wiki/Schwarzschild_radius
Aside: The observable universe's mass has a Schwarzschild radius of approximately 13.7 billion light years!

Approximately only if you include dark energy in the "observable universe's mass", in which case it is about 14.4 billion light years. This is rather the Hubble radius, because I do not think a Schwarzschild radius makes much sense on cosmic scales.

 

[Garth]

Yes, let's do the Maths:

Now the cosmological critical density is given by:

And the Schwarzschild radius is given by:

The density of mass in a sphere (Euclidean - flat - geometry) is given by:
\rho = \frac{3m}{4\pi r^3}
So the Schwarzschild density - the average density of a mass within the Schwarzschild radius is given by substituting for m from the formula for r_s :
\rho_s = \frac{3c^2}{8\pi Gr^2}
And as the age of our universe is equal to or almost equal to Hubble time (due to a fortuitous coincidence in the effect of DE - see Age of universe) we can set H = c/r so:
\rho_s = \frac{3H^2}{8\pi G}
The critical density!

But as Jorrie said "I do not think a Schwarzschild radius makes much sense on cosmic scales"

In fact we can go further, the Schwarzschild solution is a solution of the GR One Body Problem embedded in a Minkowski space-time - it is totally inappropriate to apply it to the GR cosmological solution. The similarity of the numbers just gives a feel of how the GR Field Equation works in the two solutions, one the 'static spherically symmetric solution' and the other the 'maximally symmetric space solution' - nothing more.

Garth

 

[Tanelorn]

This wiki page describes all known alternative Cosmologies:
http://en.wikipedia.org/wiki/Non-standard_cosmology

 

[Garth]

This wiki page describes all known alternative Cosmologies:
http://en.wikipedia.org/wiki/Non-standard_cosmology

Not quite all: Gravity

Alternative theories

Recent alternative theories

Brans–Dicke theory of gravity (1961) [31]
Induced gravity (1967), a proposal by Andrei Sakharov according to which general relativity might arise from quantum field theories of matter
ƒ(R) gravity (1970)
Horndeski theory (1974) [32]
Supergravity (1976)
String theory
In the modified Newtonian dynamics (MOND) (1981), Mordehai Milgrom proposes a modification of Newton's Second Law of motion for small accelerations [33]
The self-creation cosmology theory of gravity (1982) by G.A. Barber in which the Brans-Dicke theory is modified to allow mass creation
Loop quantum gravity (1988) by Carlo Rovelli, Lee Smolin, and Abhay Ashtekar
Nonsymmetric gravitational theory (NGT) (1994) by John Moffat
Tensor–vector–scalar gravity (TeVeS) (2004), a relativistic modification of MOND by Jacob Bekenstein
Gravity as an entropic force, gravity arising as an emergent phenomenon from the thermodynamic concept of entropy.
In the superfluid vacuum theory the gravity and curved space-time arise as a collective excitation mode of non-relativistic background superfluid.
Chameleon theory (2004) by Justin Khoury and Amanda Weltman.
Pressuron theory (2013) by Olivier Minazzoli and Aurélien Hees.

(emphasis mine -if I may?)

Garth

 

[Tanelorn]

The most massive structure at a distance of 7.5B Light years:

http://phys.org/news/2011-04-massive-distant.html#nRlv
One of the most interesting results of this discovery is that, if current models of how the universe evolved are accurate, clusters of this size are very rare in the young universe. In fact, this cluster could even be unique.

http://phys.org/news/2010-10-ghosts-future-giant-universe.html#nRlv
Even at that young age, the cluster was almost as massive as the nearby Coma cluster. Since then, it should have grown about four times larger. If we could see it as it appears today, it would be one of the most massive galaxy clusters in the universe.