Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Sloan Digital Sky Survey Reverberation Mapping Project: H$\alpha$
  and H$\beta$ Reverberation Measurements From First-year Spectroscopy and
  Photometry   We present reverberation mapping results from the first year of combined
spectroscopic and photometric observations of the Sloan Digital Sky Survey
Reverberation Mapping Project. We successfully recover reverberation time
delays between the $g+i$-band emission and the broad H$\beta$ emission line for
a total of 44 quasars, and for the broad H$\alpha$ emission line in 18 quasars.
Time delays are computed using the JAVELIN and CREAM software and the
traditional interpolated cross-correlation function (ICCF): Using well defined
criteria, we report measurements of 32 H$\beta$ and 13 H$\alpha$ lags with
JAVELIN, 42 H$\beta$ and 17 H$\alpha$ lags with CREAM, and 16 H$\beta$ and 8
H$\alpha$ lags with the ICCF. Lag values are generally consistent among the
three methods, though we typically measure smaller uncertainties with JAVELIN
and CREAM than with the ICCF, given the more physically motivated light curve
interpolation and more robust statistical modeling of the former two methods.
The median redshift of our H$\beta$-detected sample of quasars is 0.53,
significantly higher than that of the previous reverberation-mapping sample. We
find that in most objects, the time delay of the H$\alpha$ emission is
consistent with or slightly longer than that of H$\beta$. We measure black hole
masses using our measured time delays and line widths for these quasars. These
black hole mass measurements are mostly consistent with expectations based on
the local M-sigma relationship, and are also consistent with single-epoch black
hole mass measurements. This work increases the current sample size of
reverberation-mapped active galaxies by about two-thirds and represents the
first large sample of reverberation mapping observations beyond the local
universe (z < 0.3).

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The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: nlin
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex