PDA

View Full Version : Black Holes or Galaxies, Which Came First?



ToSeek
2004-Nov-09, 06:53 PM
Black Holes or Galaxies, Which Came First? (http://www.universetoday.com/am/publish/black_holes_galaxies_which_first.html?9112004)


Since supermassive black holes were first discovered, astronomers have been wondering if the hole was created first, and then the galaxy formed around it, or if these monsters tend to form at the heart of galaxies over time. Astronomers using the National Radio Astronomy Observatory's Very Large Array have discovered a distant galaxy that's less than a billion years old, but seems to have a supermassive black hole - but no massive bulge of stars. The black hole is 1 billion solar masses, so it should be surrounded by several trillion solar masses in stars. This provides evidence that it's the black hole that forms first, then the galaxy.

pghnative
2004-Nov-09, 06:54 PM
You've been ToSeeked (http://www.badastronomy.com/phpBB/viewtopic.php?t=17528)! :D

Glom
2004-Nov-09, 08:31 PM
pghnative ToSeeked my pointing out of ToSeek being ToSeeked.

kg034
2004-Nov-10, 08:05 AM
You've been ToSeeked (http://www.badastronomy.com/phpBB/viewtopic.php?t=17528)! :D

hehee :D...scene from Scarface:
Bistro owner: "Hey, where you goin'? Come back and wash the dishes!"
Tony Montana: "You can wash the dishes yourself, mate.... I retire!

Glutomoto
2004-Nov-10, 10:09 AM
Maybe the SMBH and the Galaxzy formed together, or that is what a discovery science channel program said.

Actually the program, Supermassive Black Holes (http://science.discovery.com/schedule/episode.jsp?episode=0&cpi=23567&gid=0&channel=SCI) claimed they were sure that both formed together, due to the relation(ratio?) of the size of the SMBH and the rotational speed of the stars(the Sigma) of the host galaxzy.

If this relationship is true, would that mean that less or no, dark matter is needed to explain why galaxzies spin so fast for their size ?

:)

ngc3314
2004-Nov-10, 01:35 PM
Maybe the SMBH and the Galaxzy formed together, or that is what a discovery science channel program said.

Actually the program, Supermassive Black Holes (http://science.discovery.com/schedule/episode.jsp?episode=0&cpi=23567&gid=0&channel=SCI) claimed they were sure that both formed together, due to the relation(ratio?) of the size of the SMBH and the rotational speed of the stars(the Sigma) of the host galaxzy.

If this relationship is true, would that mean that less or no, dark matter is needed to explain why galaxzies spin so fast for their size ?

:)

Doesn't change things much - the "canonical" relation is that the SMBH has about 1/200 of the mass found in stars in the surrounding bulge, so not a significant part of the required "dark" matter at all.

This new report is quite cool - there have been a few suggestions as to how an SMBH could be formed without slowly eating material from its surroundings within a galaxy, and those preprints will start to look much jmore relevant...