Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First Stellar Velocity Dispersion Measurement of a Luminous Quasar Host
  with Gemini North Laser Guide Star Adaptive Optics   We present the first use of the Gemini North laser guide star adaptive optics
(LGS AO) system and an integral field unit (IFU) to measure the stellar
velocity dispersion of the host of a luminous quasar. The quasar PG1426+015
(z=0.086) was observed with the Near-Infrared Integral Field Spectrometer
(NIFS) on the 8m Gemini North telescope in the H-band as part of the Science
Verification phase of the new ALTAIR LGS AO system. The NIFS IFU and LGS AO are
well suited for host studies of luminous quasars because one can achieve a
large ratio of host to quasar light. We have measured the stellar velocity
dispersion of PG1426+015 from 0.1'' to 1'' (0.16 kpc to 1.6 kpc) to be 217+/-15
km/s based on high signal-to-noise ratio measurements of Si I, Mg I, and
several CO bandheads. This new measurement is a factor of four more precise
than a previous measurement obtained with long-slit spectroscopy and good,
natural seeing, yet was obtained with a shorter net integration time. We find
that PG1426+015 has a velocity dispersion that places it significantly above
the M-sigma relation of quiescent galaxies and lower-luminosity active galactic
nuclei with black hole masses estimated from reverberation mapping. We discuss
several possible explanations for this discrepancy that could be addressed with
similar observations of a larger sample of luminous quasars.

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The categories of this paper are: math
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: q-alg
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: physics
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The categories of this paper are: comp-gas
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The categories of this paper are: cs