# Can a primitive galaxy nova or supernova?

## Main Question or Discussion Point

Can a primitive galaxy nova or supernova? Might the former process be involved with star production or the latter with a quasar?

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Can that which drives a nova or supernova be present thoughtout a galaxy?

Chronos
Gold Member
Huh? A whole galaxy? Its not even March, much less April 1.

Perhaps, if a significant mass of a galaxy collapses, it does so all they way to a black hole (quasar?) without any obvious stages like a star. However would we describe the formation of our Galaxy's supermassive black hole in terms of its effect on the outlying galactic nucleus?

Nabeshin
Perhaps, if a significant mass of a galaxy collapses, it does so all they way to a black hole (quasar?) without any obvious stages like a star.
This doesn't happen.

Collapse of any appreciable portion of a galaxy's mass would proceed so slowly and non-uniformly as to either not directly collapse into a black hole or simply create one (or even several) stellar-mass black hole with accreting matter.

You cannot create a stellar object above ~150 solar masses anyways, because the increase in temperature as the cloud collapses causes it to expand again. As far as I know, collapse of masses larger than this must proceed via fragmentation rather than a unified collapse.

Nabeshin,

"Fragmentation" suggests what I had been looking for. How does this proceed in the early universe?

Chronos
Gold Member
Might we eventually understand the origin of the dark matter velocity anisotropy?
http://arxiv.org/abs/0812.1048
Im not suggesting this is particularly mainstream, but might be along the lines you are thinking.

Nabeshin
Nabeshin,

"Fragmentation" suggests what I had been looking for. How does this proceed in the early universe?
I'm not sure if there's a very good description of how this proceeds, especially in the early universe. I don't exactly keep up with published papers, and know of no good explanation off the top of my head.

This touches on an important issue:

how do supermassive black holes (SMBH) form so quickly in the early universe?

We've detected quasars, whose energy output suggests that they are powered by SMBHs with a mass of $10^9 M_{sun}$, and that show redshifts greater than 6. This implies that a SMBH must have formed less than a billion years after the big bang. Why is this a problem? Accretion onto SMBHs is limited. If the accretion disk around a SMBH produces too much light then the photon pressure will overwhelm gravity and push the accreting matter away--thus the Eddington limit is born. Thus you can guess how fast the SMBH can grow and, sure enough, they can't grow fast enough to reach $10^9 M_{sun}$ in a billion years.

This why workers are seeking ways to circumvent the Eddington limit either by the collapse of mini dark matter halos (similar to what your saying) much more massive than a solar mass or other means.