Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Starburst Intensity Limit of Galaxies at z~5-6   The peak star formation intensity in starburst galaxies does not vary
significantly from the local universe to redshift z~6. We arrive at this
conclusion through new surface brightness measurements of 47 starburst galaxies
at z~5-6, doubling the redshift range for such observations. These galaxies are
spectroscopically confirmed in the Hubble Ultra Deep Field (HUDF) through the
GRism ACS program for Extragalactic Science (GRAPES) project. The starburst
intensity limit for galaxies at z~5-6 agree with those at z~3-4 and z~0 to
within a factor of a few, after correcting for cosmological surface brightness
dimming and for dust. The most natural interpretation of this constancy over
cosmic time is that the same physical mechanisms limit starburst intensity at
all redshifts up to z~6 (be they galactic winds, gravitational instability, or
something else). We do see two trends with redshift: First, the UV spectral
slope of galaxies at z~5-6 is bluer than that of z~3 galaxies, suggesting an
increase in dust content over time. Second, the galaxy sizes from z~3 to z~6
scale approximately as the Hubble parameter 1/H(z). Thus, galaxies at z~6 are
high redshift starbursts, much like their local analogs except for slightly
bluer colors, smaller physical sizes, and correspondingly lower overall
luminosities. If we now assume a constant maximum star formation intensity, the
differences in observed surface brightness between z~0 and z~6 are consistent
with standard expanding cosmology and strongly inconsistent with tired light
model.

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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
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The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
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The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
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The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
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The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph