J/ApJS/199/3 The quasars MMT-BOSS pilot survey (Ross+, 2012)
The SDSS-III Baryon Oscillation Spectroscopic Survey: quasar target selection
for data release nine.
Ross N.P., Myers A.D., Sheldon E.S., Yeche C., Strauss M.A., Bovy J.,
Kirkpatrick J.A., Richards G.T., Aubourg E., Blanton M.R., Brandt W.N.,
Carithers W.C., Croft R.A.C., da Silva R., Dawson K., Eisenstein D.J.,
Hennawi J.F., Ho S., Hogg D.W., Lee K.-G., Lundgren B., McMahon R.G.,
Miralda-Escude J., Palanque-Delabrouille N., Paris I., Petitjean P.,
Pieri M.M., Rich J., Roe N.A., Schiminovich D., Schlegel D.J.,
Schneider D.P., Slosar A.Z., Suzuki N., Tinker J.L., Weinberg D.H.,
Weyant A., White M., Wood-Vasey W.M.
<Astrophys. J. Suppl. Ser., 199, 3 (2012)>
=2012ApJS..199....3R 2012ApJS..199....3R
ADC_Keywords: Photometry, SDSS ; Redshifts ; QSOs ; Surveys
Keywords: cosmology: observations - intergalactic medium - surveys -
quasars: absorption lines - quasars: general -
techniques: miscellaneous
Abstract:
The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a
five-year spectroscopic survey of 10000deg2, achieved first light in
late 2009. One of the key goals of BOSS is to measure the signature of
baryon acoustic oscillations (BAOs) in the distribution of Lyα
absorption from the spectra of a sample of ∼150000 z>2.2 quasars.
Along with measuring the angular diameter distance at z∼2.5, BOSS will
provide the first direct measurement of the expansion rate of the
universe at z>2. One of the biggest challenges in achieving this goal
is an efficient target selection algorithm for quasars in the redshift
range 2.2<z<3.5, where their colors tend to overlap those of the far
more numerous stars. During the first year of the BOSS survey, quasar
target selection (QTS) methods were developed and tested to meet the
requirement of delivering at least 15 quasars/deg2 in this redshift
range, with a goal of 20 out of 40 targets/deg2 allocated to the
quasar survey. To achieve these surface densities, the magnitude limit
of the quasar targets was set at g≤22.0 or r≤21.85. We have defined
a uniformly selected subsample of 20 targets/deg2, for which the
selection efficiency is just over 50% (∼10 z>2.20 quasars/deg2).
This "CORE" subsample will be fixed for Years Two through Five of the
survey. In this paper, we describe the evolution and implementation of
the BOSS QTS algorithms during the first two years of BOSS operations
(through 2011 July), in support of the science investigations based on
these data, and we analyze the spectra obtained during the first year.
During this year, 11263 new z>2.20 quasars were spectroscopically
confirmed by BOSS, roughly double the number of previously known
quasars with z>2.20. Our current algorithms select an average of 15
z>2.20 quasars/deg2 from 40 targets/deg2 using single-epoch SDSS
imaging.
Description:
The Sloan Digital Sky Survey is now in its third phase (SDSS-III;
Eisenstein et al. 2011AJ....142...72E 2011AJ....142...72E) and is carrying out a
combination of four interleaved surveys that will continue until the
summer of 2014. One of those surveys, the Baryon Oscillation
Spectroscopic Survey (BOSS), commenced operations in late 2009 and is
using essentially all the dark time for SDSS-III. BOSS uses the same
2.5m Sloan Foundation telescope that was used in SDSS-I/II, but since
BOSS will observe fainter targets, the fiber-fed spectrographs have
been significantly upgraded. These upgrades include: new CCDs with
improved blue and red response; 1000 2" instead of 640 3" optical
diameter fibers; higher throughput gratings over a spectral range of
3600-10000Å at a resolution of about 2000, and improved optics.
Prior to the commencement of BOSS spectroscopy, we carried out
spectroscopy of quasar candidates selected from co-added photometry in
SDSS Stripe 82. Observations of these candidates were carried out in
queue mode between 2008 September and 2009 January using the Hectospec
multi-fiber spectrograph on the 6.5m Multiple Mirror Telescope (MMT).
In Tables 14 and 15, we provide positions, PSF photometry (as
observed, uncorrected for Galactic extinction), and redshifts for
confirmed quasars from the MMT survey. Objects that are not flagged
Primary in the CAS are listed separately (table 15).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table14.dat 94 437 Quasars discovered in the MMT survey
table15.dat 94 7 Quasars discovered in the MMT survey that are
non-primary in SDSS DR8 imaging
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See also:
II/306 : The SDSS Photometric Catalog, Release 8 (Adelman-McCarthy+, 2011)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
J/A+A/525/A37 : Variability indexes of QSOs in SDSS Stripe 82 (Meusinger+,
2011)
J/MNRAS/392/19 : The 2dF-SDSS QSO survey (Croom+, 2009)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/AJ/131/2788 : Redshifts in the SFQS survey (Jiang+, 2006)
http://www.sdss3.org/surveys/boss.php : BOSS home page
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1[45].dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs Second of Right Ascension (J2000)
13 A1 --- DE- Sign of the Declination (J2000)
14- 15 I2 deg DEd Degree of Declination (J2000)
17- 18 I2 arcmin DEm Arcminute of Declination (J2000)
20- 23 F4.1 arcsec DEs Arcsecond of Declination (J2000)
25- 30 F6.3 mag umag SDSS-DR8 u band magnitude (1)
32- 36 F5.3 mag e_umag Error in umag
38- 43 F6.3 mag gmag SDSS-DR8 g band magnitude (1)
45- 49 F5.3 mag e_gmag Error in umag
51- 56 F6.3 mag rmag SDSS-DR8 r band magnitude (1)
58- 62 F5.3 mag e_rmag Error in umag
64- 69 F6.3 mag imag SDSS-DR8 i band magnitude (1)
71- 75 F5.3 mag e_imag Error in umag
77- 82 F6.3 mag zmag SDSS-DR8 z band magnitude (1)
84- 88 F5.3 mag e_zmag Error in umag
90- 94 F5.3 --- z Redshift
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Note (1): Many of these objects were subsequently confirmed in the SDSS DR7
quasar catalog (Cat. VII/260) or in the BOSS (SDSS-III Baryon
Oscillation Spectroscopic Survey). Imaging information is taken from
the SDSS DR8 Catalog Archive Server (http://www.sdss3.org/dr8/).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 21-Mar-2012