Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ionisation-induced star formation I: The collect and collapse model   We conduct Smoothed Particle Hydrodynamics simulations of the `collect and
collapse' scenario (Elmegreen and Lada, 1977) for star formation triggered by
an expanding HII region. We simulate the evolution of a spherical uniform
molecular cloud with an ionising source at its centre. The gas in the cloud is
self-gravitating, although the cloud is prevented from globally collapsing. We
find that the shell driven by the HII region fragments to form numerous
self--gravitating objects. We repeat our calculations at four numerical
resolutions to ensure that they are converged. We compare our results to the
analytical model of Whitworth et al, 1994 and show that our simulations and the
predictions of Whitworth et al are in good agreement in the sense that the
shell fragments at the time and radius predicted by Whitworth et al to within
20% and 25% respectively. Most of the fragments produced in our two highest
resolution calculations are approximately half the mass of those predicted, but
this conclusion is robust against both numerical resolution and the presence of
random noise (local fluctuations in density of a factor of $\sim2$) in the
initial gas distribution. We conclude that such noise has little impact on the
fragmentation process.

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The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
21
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
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat