Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Enrichment History of the Intergalactic Medium: Measuring the CIV/HI
  Ratio in the Lyman Alpha Forest   We have obtained an exceptionally high S/N, high resolution spectrum of the
gravitationally lensed quasar Q1422+231 in order to investigate the metal
enrichment of the IGM. A column density distribution function (CDDF) is
determined for CIV, which is well fit by a power law with index 1.44 +/- 0.05.
Once a correction for incompleteness is applied, we find that the CDDF is
consistent with a power law down to log N(CIV) = 11.75, a factor of 10 more
sensitive than previously determined. In order to determine whether the CIV
enrichment extends to even lower column density HI clouds, we find that an
analysis of individual pixel optical depths is more robust than the stacking
technique. The results obtained from this optical depth method are compared
with analyses of simulated spectra enriched with varying CIV enrichment
recipes. From these simulations, we conclude that more CIV than is currently
directly detected in Q1422+231 is required to reproduce the optical depths
determined from the data, consistent with the conclusions drawn from
consideration of the power law distribution. (Abridged)

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The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
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The categories of this paper are: eess
11
The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph