Spectroscopic target selection in the sloan digital sky survey: The quasar sample

Gordon T. Richards; Xiaohui Fan; Heidi Jo Newberg; Michael A. Strauss; Daniel E. Vanden Berk; Donald P. Schneider; Brian Yanny; Adam Boucher; Scott Burles; Joshua A. Frieman; James E. Gunn; Patrick B. Hall; Željko Ivezić; Stephen Kent; Jon Loveday; Robert H. Lupton; Constance M. Rockosi; David J. Schlegel; Chris Stoughton; Mark SubbaRao; Donald G. York

doi:10.1086/340187

Spectroscopic target selection in the sloan digital sky survey: The quasar sample

Gordon T. Richards, Xiaohui Fan, Heidi Jo Newberg, Michael A. Strauss, Daniel E. Vanden Berk, Donald P. Schneider, Brian Yanny, Adam Boucher, Scott Burles, Joshua A. Frieman, James E. Gunn, Patrick B. Hall, Željko Ivezić, Stephen Kent, Jon Loveday, Robert H. Lupton, Constance M. Rockosi, David J. Schlegel, Chris Stoughton, Mark SubbaRaoDonald G. York

Research output: Contribution to journal › Review article › peer-review

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Abstract

We describe the algorithm for selecting quasar candidates for optical spectroscopy in the Sloan Digital Sky Survey. Quasar candidates are selected via their nonstellar colors in ugriz broadband photometry and by matching unresolved sources to the FIRST radio catalogs. The automated algorithm is sensitive to quasars at all redshifts lower than z ∼ 5.8. Extended sources are also targeted as low-redshift quasar candidates in order to investigate the evolution of active galactic nuclei (AGNs) at the faint end of the luminosity function. Nearly 95% of previously known quasars are recovered (based on 1540 quasars in 446 deg²). The overall completeness, estimated from simulated quasars, is expected to be over 90%, whereas the overall efficiency (quasars/quasar candidates) is better than 65%. The selection algorithm targets ultraviolet excess quasars to i* = 19.1 and higher redshift (z ≳ 3) quasars to i* = 20.2, yielding approximately 18 candidates deg ^-2. In addition to selecting "normal" quasars, the design of the algorithm makes it sensitive to atypical AGNs such, as broad absorption line quasars and heavily reddened quasars.

Original language	English (US)
Pages (from-to)	2945-2975
Number of pages	31
Journal	Astronomical Journal
Volume	123
Issue number	6 1758
DOIs	https://doi.org/10.1086/340187
State	Published - Jun 2002

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/340187

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Richards, G. T., Fan, X., Newberg, H. J., Strauss, M. A., Vanden Berk, D. E., Schneider, D. P., Yanny, B., Boucher, A., Burles, S., Frieman, J. A., Gunn, J. E., Hall, P. B., Ivezić, Ž., Kent, S., Loveday, J., Lupton, R. H., Rockosi, C. M., Schlegel, D. J., Stoughton, C., ... York, D. G. (2002). Spectroscopic target selection in the sloan digital sky survey: The quasar sample. Astronomical Journal, 123(6 1758), 2945-2975. https://doi.org/10.1086/340187

@article{c1c568afbd9543468c3a1a58cf4f08d4,

title = "Spectroscopic target selection in the sloan digital sky survey: The quasar sample",

abstract = "We describe the algorithm for selecting quasar candidates for optical spectroscopy in the Sloan Digital Sky Survey. Quasar candidates are selected via their nonstellar colors in ugriz broadband photometry and by matching unresolved sources to the FIRST radio catalogs. The automated algorithm is sensitive to quasars at all redshifts lower than z ∼ 5.8. Extended sources are also targeted as low-redshift quasar candidates in order to investigate the evolution of active galactic nuclei (AGNs) at the faint end of the luminosity function. Nearly 95% of previously known quasars are recovered (based on 1540 quasars in 446 deg2). The overall completeness, estimated from simulated quasars, is expected to be over 90%, whereas the overall efficiency (quasars/quasar candidates) is better than 65%. The selection algorithm targets ultraviolet excess quasars to i* = 19.1 and higher redshift (z ≳ 3) quasars to i* = 20.2, yielding approximately 18 candidates deg -2. In addition to selecting {"}normal{"} quasars, the design of the algorithm makes it sensitive to atypical AGNs such, as broad absorption line quasars and heavily reddened quasars.",

author = "Richards, {Gordon T.} and Xiaohui Fan and Newberg, {Heidi Jo} and Strauss, {Michael A.} and {Vanden Berk}, {Daniel E.} and Schneider, {Donald P.} and Brian Yanny and Adam Boucher and Scott Burles and Frieman, {Joshua A.} and Gunn, {James E.} and Hall, {Patrick B.} and {\v Z}eljko Ivezi{\'c} and Stephen Kent and Jon Loveday and Lupton, {Robert H.} and Rockosi, {Constance M.} and Schlegel, {David J.} and Chris Stoughton and Mark SubbaRao and York, {Donald G.}",

year = "2002",

month = jun,

doi = "10.1086/340187",

language = "English (US)",

volume = "123",

pages = "2945--2975",

journal = "Astronomical Journal",

issn = "0004-6256",

publisher = "IOP Publishing Ltd.",

number = "6 1758",

}

Richards, GT, Fan, X, Newberg, HJ, Strauss, MA, Vanden Berk, DE, Schneider, DP, Yanny, B, Boucher, A, Burles, S, Frieman, JA, Gunn, JE, Hall, PB, Ivezić, Ž, Kent, S, Loveday, J, Lupton, RH, Rockosi, CM, Schlegel, DJ, Stoughton, C, SubbaRao, M & York, DG 2002, 'Spectroscopic target selection in the sloan digital sky survey: The quasar sample', Astronomical Journal, vol. 123, no. 6 1758, pp. 2945-2975. https://doi.org/10.1086/340187

TY - JOUR

T1 - Spectroscopic target selection in the sloan digital sky survey

T2 - The quasar sample

AU - Richards, Gordon T.

AU - Fan, Xiaohui

AU - Newberg, Heidi Jo

AU - Strauss, Michael A.

AU - Vanden Berk, Daniel E.

AU - Schneider, Donald P.

AU - Yanny, Brian

AU - Boucher, Adam

AU - Burles, Scott

AU - Frieman, Joshua A.

AU - Gunn, James E.

AU - Hall, Patrick B.

AU - Ivezić, Željko

AU - Kent, Stephen

AU - Loveday, Jon

AU - Lupton, Robert H.

AU - Rockosi, Constance M.

AU - Schlegel, David J.

AU - Stoughton, Chris

AU - SubbaRao, Mark

AU - York, Donald G.

PY - 2002/6

Y1 - 2002/6

N2 - We describe the algorithm for selecting quasar candidates for optical spectroscopy in the Sloan Digital Sky Survey. Quasar candidates are selected via their nonstellar colors in ugriz broadband photometry and by matching unresolved sources to the FIRST radio catalogs. The automated algorithm is sensitive to quasars at all redshifts lower than z ∼ 5.8. Extended sources are also targeted as low-redshift quasar candidates in order to investigate the evolution of active galactic nuclei (AGNs) at the faint end of the luminosity function. Nearly 95% of previously known quasars are recovered (based on 1540 quasars in 446 deg2). The overall completeness, estimated from simulated quasars, is expected to be over 90%, whereas the overall efficiency (quasars/quasar candidates) is better than 65%. The selection algorithm targets ultraviolet excess quasars to i* = 19.1 and higher redshift (z ≳ 3) quasars to i* = 20.2, yielding approximately 18 candidates deg -2. In addition to selecting "normal" quasars, the design of the algorithm makes it sensitive to atypical AGNs such, as broad absorption line quasars and heavily reddened quasars.

AB - We describe the algorithm for selecting quasar candidates for optical spectroscopy in the Sloan Digital Sky Survey. Quasar candidates are selected via their nonstellar colors in ugriz broadband photometry and by matching unresolved sources to the FIRST radio catalogs. The automated algorithm is sensitive to quasars at all redshifts lower than z ∼ 5.8. Extended sources are also targeted as low-redshift quasar candidates in order to investigate the evolution of active galactic nuclei (AGNs) at the faint end of the luminosity function. Nearly 95% of previously known quasars are recovered (based on 1540 quasars in 446 deg2). The overall completeness, estimated from simulated quasars, is expected to be over 90%, whereas the overall efficiency (quasars/quasar candidates) is better than 65%. The selection algorithm targets ultraviolet excess quasars to i* = 19.1 and higher redshift (z ≳ 3) quasars to i* = 20.2, yielding approximately 18 candidates deg -2. In addition to selecting "normal" quasars, the design of the algorithm makes it sensitive to atypical AGNs such, as broad absorption line quasars and heavily reddened quasars.

UR - http://www.scopus.com/inward/record.url?scp=0012314515&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0012314515&partnerID=8YFLogxK

U2 - 10.1086/340187

DO - 10.1086/340187

M3 - Review article

AN - SCOPUS:0012314515

SN - 0004-6256

VL - 123

SP - 2945

EP - 2975

JO - Astronomical Journal

JF - Astronomical Journal

IS - 6 1758

ER -

Spectroscopic target selection in the sloan digital sky survey: The quasar sample

Abstract

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