Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Velocity-Metallicity Correlation for high-z DLA Galaxies: Evidence for a
  Mass-Metallicity Relation?   We used our database of VLT-UVES quasar spectra to build up a sample of 70
Damped Lyman-alpha (DLA) or strong sub-DLA systems with total neutral hydrogen
column densities of log N(HI)>20 and redshifts in the range 1.7<z_abs<4.3. For
each of the systems, we measured in an homogeneous manner the metallicities
relative to Solar, [X/H] (with X=Zn, or S or Si), and the velocity widths of
low-ionization line profiles, Delta V. We provide for the first time evidence
for a correlation between DLA metallicity and line profile velocity width,
which is detected at the 6.1sigma significance level. This confirms the trend
previously observed in a much smaller sample by Wolfe & Prochaska (1998). The
best-fit linear relation is [X/H]=1.55(\pm 0.12) log Delta V -4.33(\pm 0.23)
with Delta V expressed in km/s. The slope of the DLA velocity-metallicity
relation is the same within uncertainties between the higher (z_abs>2.43) and
the lower (z_abs<2.43) redshift halves of our sample. However, the two
populations of systems are statistically different. There is a strong redshift
evolution in the sense that the mean metallicity and mean velocity width
increase with decreasing redshift. We argue that the existence of a DLA
velocity-metallicity correlation, over more than a factor of 100 spread in
metallicity, is probably the consequence of an underlying mass-metallicity
relation for the galaxies responsible for DLA absorption lines. Assuming a
simple linear scaling of the galaxy luminosity with the mass of the dark-matter
halo, we find that the slope of the DLA velocity-metallicity relation is
consistent with that of the luminosity-metallicity relation derived for local
galaxies. [...] abridged.

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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: stat
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The categories of this paper are: bayes-an