On Sunday, May 10, 2015 at 9:40:43 PM UTC-4, brad wrote:
=20
IMO this is easily explained by revising the current cosmological
model whereby black holes grow with galaxies. If we remember that
the first stars were massive and that matter was unevenly distributed
in the early Universe; then we can accept that, in addition to
massive first generation stars there must also have been large
agglomerations of matter that spontaneously collapsed into massive
black holes. =20

Let me flesh this out a little. For gravitational collapse to proceed
to the formation of some object the combined angular momentum of
infalling material cannot exceed a value that prohibits collapse.
This can be accomplished if there is material available to carry
away angular momentum. In the early Universe there was essentially
an unlimited amount of matter available to carry away angular momentum
allowing much more massive objects to result before the developing
object could clear a volume around itself.

[[Mod. note -- As well as low angular momentum, collapse also needs
low internal pressure.

It's instructive to consider the question of why the Sun *today*
doesn't collapse to form a black hole? The Sun currently has a radius
of about 700,000 km. To form a black hole, it (or a 1-solar-mass gas
cloud of the same size) would have to be compressed to a radius of
around 3 km, i.e., a compression by around a factor of
10,000,000,000,000,000 in volume. That would take HUGE compressive
forces... which don't seem to be available in star-forming regions.

By working out the collapse physics in detail, you can model a
protostar's collapse and estimate roughly the
radius/temperature/luminosity at which it will halt. See
http://en.wikipedia.org/wiki/Hayashi_track
for a nice introduction.
-- jt]]

That means the seeds of galaxies can come first! The
gravitational energy from spinning black holes in the midst the
remaining un-collapsed matter would then cause star birth and
galactic structure. This doesn't mean black holes don't grow, only
that galactic nuclei can come earlier than the present model predicts
=20
[[Mod. note -- The problem with this scenario is in the details:
* Large agglomerations of matter" at early-universe densities won't
actually collapse to form black holes: the matter's random motions
imply that it has some (small) amount of angular momentum, and
this blocks collapse.
* Precisely how does the "gravitational energy from spinning black
holes" cause star formation?
-- jt]]
=20
Brad J.