**AAS 206th Meeting, 29 May - 2 June 2005**

*Session 7 Star Formation*

Poster, Monday, 9:20am-6:30pm, Tuesday, 10:00am-7:00pm, May 30, 2005, Ballroom A
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## [7.09] Generalized Collapse Solutions with Initial Velocities for Star Formation in Molecular Cloud Cores

*M. Fatuzzo (Xavier University), F. C. Adams (University of Michigan), P. C. Myers (Harvard Smithsonian CfA)*

Motivated by recent observations that show starless
molecular cloud cores exhibit subsonic inward velocities, we
revisit the collapse problem for polytropic gaseous spheres.
In particular, we provide a generalized treatment of
protostellar collapse in the spherical limit and find
semi-analytic (self-similar) solutions, corresponding
numerical solutions, and purely analytic calculations of the
mass infall rates (the three approaches are in good
agreement). This study focuses on collapse solutions that
exhibit nonzero inward velocities at large radii, as
observed in molecular cloud cores, and extends previous work
in four ways: (1) The initial conditions allow nonzero
initial inward velocity. (2) The starting states can exceed
the density of hydrostatic equilibrium so that the collapse
itself can provide the observed inward motions. (3) We
consider different equations of state, especially those that
are softer than isothermal. (4) We consider dynamic
equations of state that are different from the effective
equation of state that produces the initial density
distribution. This work determines the infall rates over a
wide range of parameter space, as characterized by four
variables: the initial inward velocity, the overdensity of
the initial state, the index of the static equation of
state, and the index of the dynamic equation of state. For
the range of parameter space applicable to observed cores,
the resulting infall rate is about a factor of two larger
than found in previous theoretical studies (those with
hydrostatic initial conditions and no initial inward
velocity).

The author(s) of this abstract have provided an email address
for comments about the abstract:
fatuzzo@xavier.edu

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Bulletin of the American Astronomical Society, **37** #2

© 2005. The American Astronomical Soceity.