Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self-Regulation of Star Formation in Low Metallicity Clouds   We investigate the process of self-regulated star formation via
photodissociation of hydrogen molecules in low metallicity clouds. We evaluate
the influence region's scale of a massive star in low metallicity gas clouds
whose temperatures are between 100 and 10000 Kelvin. A single O star can
photodissociate hydrogen molecules in the whole of the host cloud. If
metallicity is smaller than about 10^{-2.5} of the solar metallicity, the
depletion of coolant of the the host cloud is very serious so that the cloud
cannot cool in a free-fall time, and subsequent star formation is almost
quenched. On the contrary, if metallicity is larger than about 10^{-1.5} of the
solar metallicity, star formation regulation via photodissociation is not
efficient. The typical metallicity when this transition occurs is about 1/100
of the solar metallicity. This indicates that stars do not form efficiently
before the metallicity becomes larger than about 1/100 of the solar metallicity
and we considered that this value becomes the lower limit of the metallicity of
luminous objects such as galaxies.

25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph