Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collapse in Self-gravitating Turbulent Fluids   Motivated by the nonlinear star formation efficiency found in recent
numerical simulations by a number of workers, we perform high-resolution
adaptive mesh refinement simulations of star formation in self-gravitating
turbulently driven gas. As we follow the collapse of this gas, we find that the
character of the flow changes at two radii, the disk radius $r_d$, and the
radius $r_*$ where the enclosed gas mass exceeds the stellar mass. Accretion
starts at large scales and works inwards. In line with recent analytical work,
we find that the density evolves to a fixed attractor, $\rho(r,t ) \rightarrow
\rho(r)$, for $r_d<r<r_*$; mass flows through this structure onto a
sporadically gravitationally unstable disk, and from thence onto the star. In
the bulk of the simulation box we find that the random motions $v_T \sim r^p$
with $p \sim 0.5$, in agreement with Larson's size-linewidth relation. In the
vicinity of massive star forming regions we find $ p \sim 0.2-0.3$, as seen in
observations. For $r<r_*$, $v_T$ increases inward, with $p=-1/2$. Finally, we
find that the total stellar mass $M_*(t)\sim t^2$ in line with previous
numerical and analytic work that suggests a nonlinear rate of star formation.

13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int