Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Eight-Dimensional Mid-Infrared/Optical Bayesian Quasar Selection   We explore the multidimensional, multiwavelength selection of quasars from
mid-IR (MIR) plus optical data, specifically from Spitzer-IRAC and the Sloan
Digital Sky Survey (SDSS). We apply modern statistical techniques to combined
Spitzer MIR and SDSS optical data, allowing up to 8-D color selection of
quasars. Using a Bayesian selection method, we catalog 5546 quasar candidates
to an 8.0 um depth of 56 uJy over an area of ~24 sq. deg; ~70% of these
candidates are not identified by applying the same Bayesian algorithm to
4-color SDSS optical data alone. Our selection recovers 97.7% of known type 1
quasars in this area and greatly improves the effectiveness of identifying
3.5<z<5 quasars. Even using only the two shortest wavelength IRAC bandpasses,
it is possible to use our Bayesian techniques to select quasars with 97%
completeness and as little as 10% contamination. This sample has a photometric
redshift accuracy of 93.6% (Delta Z +/-0.3), remaining roughly constant when
the two reddest MIR bands are excluded. While our methods are designed to find
type 1 (unobscured) quasars, as many as 1200 of the objects are type 2
(obscured) quasar candidates. Coupling deep optical imaging data with deep
mid-IR data could enable selection of quasars in significant numbers past the
peak of the quasar luminosity function (QLF) to at least z~4. Such a sample
would constrain the shape of the QLF and enable quasar clustering studies over
the largest range of redshift and luminosity to date, yielding significant
gains in our understanding of quasars and the evolution of galaxies.

33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex