The formation of massive star systems by accretion.
Massive stars produce so much light that the radiation pressure they exert on the gas and dust around them is stronger than their gravitational attraction, a condition that has long been expected to prevent them from growing by accretion. We present three-dimensional radiation-hydrodynamic simulations of the collapse of a massive prestellar core and find that radiation pressure does not halt accretion. Instead, gravitational and Rayleigh-Taylor instabilities channel gas onto the star system through nonaxisymmetric disks and filaments that self-shield against radiation while allowing radiation to escape through optically thin bubbles. Gravitational instabilities cause the disk to fragment and form a massive companion to the primary star. Radiation pressure does not limit stellar masses, but the instabilities that allow accretion to continue lead to small multiple systems.
Krumholz
Mark R
MR
Department of Astronomy, University of California, Santa Cruz, CA95064, USA. krumholz@ucolick.org
Klein
Richard I
RI
McKee
Christopher F
CF
Offner
Stella S R
SS
Cunningham
Andrew J
AJ