SM BHs, Quasars, & Starburst galaxies

[Widdekind]

Galaxies are "anchored by a Super-Massive Black Hole" (SMBH). And, that SMBH can generate a Quasar, when it is "actively-very actively- feeding on surrounding gas". Such occurred, quite commonly, in the early universe, which was much more matter dense. Or, more recently, mergers of galaxies can funnel material into central SMBHs.

 

Now, SMBHs are associated with "intense star formation". Thus, they are associated, and perhaps trigger, "'starburst' galaxies, forming stars at 10 to 15 times the rate we see in the Milky Way today". Such star-burst galaxies were much more common, in the early universe. For example, galaxy HUDF-JD2 "formed the bulk of its stars very rapidly, on time scales less than or equal to 100 Myr, and the subsequent evolution was essentially passive". And, said star-burst period happened "between 350 and 650 Myr" in cosmic time, corresponding to red-shifts "between 10 and 20".

 

Quasars were bright enough, that their light reaches us, even when reflected from surrounding material (leading to a 'light echo').

[Airbrush]

"Galaxies are "anchored by a ...what-turns-the-super-galaxies-on/Super-Massive Black Hole..." (SMBH).

 

The word "anchored" makes it sound like SMBH are what holds a galaxy together. Their mass is relatively tiny in relation to the total mass of the central region of a galaxy. What "anchors" a galaxy is dark matter.

Edited April 16, 2011 by Airbrush

[Widdekind]

"Galaxies are "anchored by a ...what-turns-the-super-galaxies-on/Super-Massive Black Hole..." (SMBH).

 

The word "anchored" makes it sound like SMBH are what holds a galaxy together. Their mass is relatively tiny in relation to the total mass of the central region of a galaxy. What "anchors" a galaxy is dark matter.

 

Central BH's mass ~0.1% of the galactic central bulge mass (M-sigma). There is only, seemingly, a weaker correlation, and certainly secondary, between bulge & disk/galaxy:

 

In a pre-print submitted in January 19, 2011, a team of astronomers reported that the super-massive central black holes of galaxies appear to be dependent on the size of their central bulge of stars, rather than on the size of their spiral disk... Galaxies without a bulge contain very low mass black holes, if any. Hence, they concluded that the growth of super-massive black holes in galaxies is primarily dependent on the formation of a central bulge

 

http://www.solstation.com/x-objects/cenbulge.htm