Star Formation Around Supermassive Black Holes
I. A. Bonnell1* and
W. K. M. Rice2
The presence of young massive stars orbiting on eccentric rings
within a few tenths of a parsec of the supermassive black hole
in the galactic center is challenging for theories of star formation.
The high tidal shear from the black hole should tear apart the
molecular clouds that form stars elsewhere in the Galaxy, and
transport of stars to the galactic center also appears unlikely
during their lifetimes. We conducted numerical simulations of
the infall of a giant molecular cloud that interacts with the
black hole. The transfer of energy during closest approach allows
part of the cloud to become bound to the black hole, forming
an eccentric disk that quickly fragments to form stars. Compressional
heating due to the black hole raises the temperature of the
gas up to several hundred to several thousand kelvin, ensuring
that the fragmentation produces relatively high stellar masses.
These stars retain the eccentricity of the disk and, for a sufficiently
massive initial cloud, produce an extremely top-heavy distribution
of stellar masses. This potentially repetitive process may explain
the presence of multiple eccentric rings of young stars in the
presence of a supermassive black hole.
2 Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK.
* To whom correspondence should be addressed. E-mail: iab1{at}st-andrews.ac.uk
