Richard I. Klein,
Robert Fisher,
Christopher McKee,
Mark Krumholz
The Collapse and Fragmentation of Turbulent Molecular Cloud Cores:the Formation of Low Mass stars
Developing a comprehensive theory of star formation remains one of the
most elusive, and most important, goals of theoretical astrophysics.
Stars form when dense clumps within molecular clouds undergo
gravitational collapse and fragment into smaller components that in
turn condense into stars. Basic questions concerning this process
remain unanswered. What determines the fraction of an unstable cloud
that will fragment into protostellar objects? What determines the
pattern of stellar clustering into binaries and multiple systems?
Even after fragmentation occurs, we have little understanding of the
subsequent collapse. Consequently, it is unclear how the mass
distribution of fragments maps onto eventual stellar masses, something
we must understand to explain the stellar initial mass function (IMF).
A great computational challenge of low mass star formation involves
following the collapse and fragmentation of molecular clouds over a
range of 20 orders of magnitude in density and 7 orders of magnitude
on spatial scale. I will discuss the development and the
implementation of the numerical AMR methodology that will contribute
to answering these questions. This methodology consists of a 3D
parallel adaptive mesh refinement (AMR) self-gravitational
radiation-hydrodynamics code that we have developed. I will present
new results for the gravitational collapse of turbulent molecular
clouds, the formation of molecular cloud cores within the clouds, and
the collapse and fragmentation of the cloud cores to form single,
binary and multiple stellar systems. I will disuss the role of
turbulence and radiation in the formation of low mass stars.