It turns out you dont have to be a giant galaxy to have a super-massive black hole.
A Hubble Space Telescope study shows even small dwarf galaxies can have big black holes.
The discovery challenges currently held theories of galaxy formation and black hole growth.
Dwarf galaxies with massive black holes may be forerunners of galaxies like our own Milky Way.
The relationship between a galaxy and its black hole is as mystifying as any of those found among families on Earth.
Scientists dont even know which came first galaxies or their black holes, those regions of space so dense with matter that even photons of light fall prey to their gravitational jaws.
Scrambling the cosmic conundrum anew is a discovery of small dwarf galaxies with giant black holes, a finding that upends currently held theories of galaxy formation.
Previous studies showed that as a galaxy grows and evolves, its black hole seems to grow and evolve too, at least for the big clusters.
Using data from the Hubble Space Telescope, astronomers now find that some small galaxies in the distant universe have disproportionately sized black holes.
They seem to be out of sync in some fundamental way, astronomer Sandra Faber, with Californias Lick Observatory, told Discovery News. These black holes are too massive given their star content at that time, Faber said.
Theyve grown up too fast. The holes have gotten ahead of the teen-age galaxies.
Even more puzzling: the telltale bulge of stars associated with super-massive black holes in large galaxies is noticeably absent in these smaller siblings, suggesting there may be more than one way to grow a black hole.
The finding is based on studies of 28 dwarf galaxies huddled together some 10 billion light years from Earth. While black holes, by definition, cannot be seen, astronomers look at the radiation streaming from stars surrounding the black hole to figure out its size and features. ...
http://news.discovery.com/space/galaxy-black-hole-110920.htm
Nature Review
The role of black holes in galaxy formation and evolution:
(22-page pdf file)
http://arxiv.org/pdf/0907.1608.pdf
Discovery of huge black hole raises doubts about how galaxies are formed:
http://www.thestar.com/news/world/2012/11/29/discovery_of_huge_black_hole_raises_doubts_about_how_galaxies_are_formed.html
This may be a discovery of exceptional gravity.