Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Early star-forming galaxies and the reionization of the Universe   Star forming galaxies represent a valuable tracer of cosmic history. Recent
observational progress with Hubble Space Telescope has led to the discovery and
study of the earliest-known galaxies corresponding to a period when the
Universe was only ~800 million years old. Intense ultraviolet radiation from
these early galaxies probably induced a major event in cosmic history: the
reionization of intergalactic hydrogen. New techniques are being developed to
understand the properties of these most distant galaxies and determine their
influence on the evolution of the universe.

22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat