J/ApJ/719/1672 SDSS binary quasars at high redshift. I. (Hennawi+, 2010)
Binary quasars at high redshift.
I. 24 new quasar pairs at z ∼ 3-4.
Hennawi J.F., Myers A.D., Shen Y., Strauss M.A., Djorgovski S.G., Fan X.,
Glikman E., Mahabal A., Martin C.L., Richards G.T., Schneider D.P.,
Shankar F.
<Astrophys. J., 719, 1672-1692 (2010)>
=2010ApJ...719.1672H 2010ApJ...719.1672H
ADC_Keywords: QSOs ; Photometry, SDSS ; Spectroscopy ; Redshifts
Keywords: cosmology: observations - large-scale structure of universe -
quasars: general - surveys
Abstract:
The clustering of quasars on small scales yields fundamental
constraints on models of quasar evolution and the buildup of
supermassive black holes. This paper describes the first systematic
survey to discover high-redshift binary quasars. Using color-selection
and photometric redshift techniques, we searched 8142deg2 of Sloan
Digital Sky Survey imaging data for binary quasar candidates, and
confirmed them with follow-up spectroscopy. Our sample of 27
high-redshift binaries (24 of them new discoveries) at redshifts
2.9<z<4.3 with proper transverse separations 10kpc<RT<650kpc
increases the number of such objects known by an order of magnitude.
Eight members of this sample are very close pairs with RT<100kpc,
and of these close systems four are at z>3.5. The completeness and
efficiency of our well-defined selection algorithm are quantified
using simulated photometry and we find that our sample is ∼50%
complete.
Description:
Discovery spectra of our binary candidates were obtained with the
Astrophysical Research Consortium 3.5m telescope at the Apache Point
Observatory (APO), the 6.5m Multiple Mirror Telescope (MMT), the
Palomar 200 inch telescope, the Mayall 4m telescope at Kitt Peak
National Observatory, and the KeckII 10m telescope from 2005 November
to 2008 June. Table 3 lists relevant quantities for a total of 27
binaries in the SDSS imaging area footprint, including three
previously known pairs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 111 54 High-redshift binary quasars in the SDSS
imaging footprint
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See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/ApJ/678/635 : Spectroscopy of quasar binary candidates (Myers+, 2008)
J/AJ/131/1 : Binary quasars in the SDSS (Hennawi+, 2006)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- [HMS2010] Brighter quasar designation
(SDSS JHHMM+DDMMA or PSS JHHMM+DDMMA) (1)
18 A1 --- f_[HMS2010] [a] PSS quasar (2)
20- 21 I2 h RAh Hour of right ascension (J2000)
23- 24 I2 min RAm Minute of right ascension (J2000)
26- 31 F6.3 s RAs Second of right ascension (J2000)
33 A1 --- DE- Sign of declination (J2000)
34- 35 I2 deg DEd Degree of declination (J2000)
37- 38 I2 arcmin DEm Arcminute of declination (J2000)
40- 44 F5.2 arcsec DEs Arcsecond of declination (J2000)
46- 50 F5.2 mag umag ? SDSS u-band magnitude (3)
52- 56 F5.2 mag gmag ? SDSS g-band magnitude (3)
58 A1 --- u_rmag [~] Uncertainty flag on rmag
59- 63 F5.2 mag rmag ? SDSS r-band magnitude (3)
65- 69 F5.2 mag imag ? SDSS i-band magnitude (3)
71- 75 F5.2 mag zmag ? SDSS z-band magnitude (3)
77- 81 F5.1 --- chi2s ? The minimum stellar locus distance
(χ2star)
83- 86 F4.1 --- chi2p ? Quasar locus distance (χ2phot)
88- 92 F5.3 --- z Redshift
94- 97 I4 km/s e_z Estimation of the redshift uncertainty
99-102 I4 km/s DelV ? Velocity difference ΔV between the
two members of a pair (primary only)
104-107 F4.1 arcsec DelT ? Angular separation Δθ
109-111 I3 kpc RT ? Transverse proper separation
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Note (1): The brightest member of the pair in the i band is always labeled
"A" and the fainter member is labeled "B."; see Note (2) for the PSS
designation.
Note (2):
a = This quasar pair was selected via a different method during a pilot
search for proto-clusters associated with z>4 quasars (see Section 4.1).
The redshifts quoted are approximate and we did not measure a velocity
difference. The fainter quasar PSS 1315+2924B is not detected in the
SDSS imaging, its quoted r-band magnitude is an estimate from Keck
LRIS R-band imaging.
Note (3): Extinction-corrected SDSS five-band point-spread function (PSF)
photometry is given in the columns umag, gmag, rmag, imag, and zmag.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 19-Jun-2012