Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Star Formation History of the Hubble Ultra Deep Field: Comparison with
  the HDFN   We use the NICMOS Treasury and ACS HUDF images to measure the extinction
corrected star formation history for 4681 galaxies in the region common to both
images utilizing the star formation rate distribution function and other
techniques similar to those employed with the NICMOS and WFPC2 images in the
HDFN. Unlike the HDFN the NICMOS region of the HUDF appears to lack highly
luminous and high star formation rate galaxies at redshifts beyond 3. The HUDF
provides a region that is completely uncorrelated to the HDFN and therefore
provides and independent measure of the star formation history of the universe.
The combined HUDF and HDFN star formation rates show an average star formation
rate of 0.2 solar masses per yer per cubic megaparsec. The average SFR of the
combined fields at z = 1-3 is 0.29 solar masses per year per cubic megaparsec
while the average at z = 4-6 is 1.2 solar masses per year per cubic megaparsec.
The SFRs at all redshifts are within 3 sigma of the average over all redshifts.

34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: supr-con