Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Emission-Line Diagnostics of Galaxy Evolution with NGST   As a byproduct of its search for the first star forming galaxies, NGST will
obtain high-quality spectra for thousands of galaxies in the redshift range z =
0 - 6 and beyond. Most of the galaxies will possess strong emission-line
spectra, and these spectra will provide a wealth of information on their star
formation rates, reddening, metal abundances, internal kinematics, and nuclear
activity. This will make it possible to construct a comprehensive picture of
the buildup of stars, metals, dust, and the nuclei of galaxies with
cosmological lookback time. This paper reviews what can be learned from the
spectra of distant emission-line galaxies. Simulations of NGST spectra are used
to explore the instrumental tradeoffss for these applications, and the
respective roles of NGST and groundbased surveys.

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The categories of this paper are: math
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas