Paper: astro-ph/0510432
Date: Fri, 14 Oct 2005 13:50:15 GMT (75kb)

Title: Radiation Pressure in Massive Star Formation

Authors: Mark R. Krumholz (1), Richard I. Klein (2 and 3), and Christopher F.
McKee (2 and 4) ((1) Department of Astrophysical Sciences, Princeton
University, (2) Department of Astronomy, University of California, Berkeley,
(3) Lawrence Livermore National Laboratory, (4) Department of Physics,
University of California, Berkeley)

Comments: To be appear in "IAU 227: Massive Star Birth: A Crossroads of
Astrophysics"; 6 pages, 1 figure
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Stars with masses of >~ 20 solar masses have short Kelvin times that enable
them to reach the main sequence while still accreting from their natal clouds.
The resulting nuclear burning produces a huge luminosity and a correspondingly
large radiation pressure force on dust grains in the accreting gas. This effect
may limit the upper mass of stars that can form by accretion. Indeed,
simulations and analytic calculations to date have been unable to resolve the
mystery of how stars of 50 solar masses and up form. We present two new ideas
to solve the radiation pressure problem. First, we use three-dimensional
radiation hydrodynamic adaptive mesh refinement simulations to study the
collapse of massive cores. We find that in three dimensions a configuration in
which radiation holds up an infalling envelope is Rayleigh-Taylor unstable,
leading radiation driven bubbles to collapse and accretion to continue. We also
present Monte Carlo radiative transfer calculations showing that the cavities
created by protostellar winds provides a valve that allow radiation to escape
the accreting envelope, further reducing the ability of radiation pressure to
inhibit accretion.

\\ ( http://arXiv.org/abs/astro-ph/0510432 , 75kb)