Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: LYMAN $\alpha$ FORESTS AND COOLING OUTFLOW FROM DWARF GALAXIES   We propose that cooling outflows from star-forming dwarf galaxies that are
spatially correlated with but unbound to bright galaxies may account for the
low column QSO Ly$\alpha$ forests, providing an explanation for both the heavy
elements recently detected in them and the large sizes associated with them.
Thus, we suggest that structure formations in the early universe on scales
where matters collapse gravitationally and the gas forms stars are responsible
for the Ly$\alpha$ forests (cf. the mini-halo model). Supernovae shock the
interstellar gas to high temperature, and the resulting gas outflows from the
dwarfs owing to their shallow potential wells. The gas cools radiatively as the
radiative cooling time shortens because of adiabatic expansion. Subsequent
thermal instability results in condensation of clouds. The clouds inherit the
kinetic energy of the flow and coast to large distances, providing regions of
the absorbing gas with sizes of up to hundreds of kpc. We calculate the
Ly$\alpha$ absorption line profiles and the neutral column distribution, and
show that they are consistent with observations. We suggest that the Ly$\alpha$
forests are caused by the faint blue galaxies found in the deep extragalactic
surveys.

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The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc