Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Line Overlap and Self-Shielding of Molecular Hydrogen in Galaxies   The effect of line overlap in the Lyman and Werner bands, often ignored in
galactic studies of the atomic-to-molecular transition, greatly enhances
molecular hydrogen self-shielding in low metallicity environments, and
dominates over dust shielding for metallicities below about 10% solar. We
implement that effect in cosmological hydrodynamics simulations with an
empirical model, calibrated against the observational data, and provide fitting
formulae for the molecular hydrogen fraction as a function of gas density on
various spatial scales and in environments with varied dust abundance and
interstellar radiation field. We find that line overlap, while important for
detailed radiative transfer in the Lyman and Werner bands, has only a minor
effect on star formation on galactic scales, which, to a much larger degree, is
regulated by stellar feedback.

17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con