The 2dF-SDSS LRG and QSO (2SLAQ) Survey

The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85

Gordon T. Richards, Scott M. Croom, Scott F. Anderson, Joss Bland-Hawthorn, Brian J. Boyle, Roberto De Propris, Michael J. Drinkwater, Xiaohui Fan, James E. Gunn, Željko Ivezić, Sebastian Jester, Jon Loveday, Avery Meiksin, Lance Miller, Adam Myers, Robert C. Nichol, Phil J. Outram, Kevin A. Pimbblet, Isaac G. Roseboom, Nie Ross & 8 others Donald P. Schneider, Tom Shanks, Robert G. Sharp, Chris Stoughton, Michael A. Strauss, Alexander S. Szalay, Daniel E. Vanden Berk, Donald G. York

Research output: Contribution to journalArticle

145 Citations (Scopus)

Abstract

We have used the Two-Degree Field (2dF) instrument on the Anglo-Australian Telescope (AAT) to obtain redshifts of a sample of z < 3 and 18.0 < g < 21.85 quasars selected from Sloan Digital Sky Survey (SDSS) imaging. These data are part of a larger joint programme between the SDSS and 2dF communities to obtain spectra of faint quasars and luminous red galaxies, namely the 2dF-SDSS LRG and QSO (2SLAQ) Survey. We describe the quasar selection algorithm and present the resulting number counts and luminosity function of 5645 quasars in 105.7 deg 2. The bright-end number counts and luminosity functions agree well with determinations from the 2dF QSO Redshift Survey (2QZ) data to g ∼ 20.2. However, at the faint end, the 2SLAQ number counts and luminosity functions are steeper (i.e. require more faint quasars) than the final 2QZ results from Croom et al., but are consistent with the preliminary 2QZ results from Boyle et al. Using the functional form adopted for the 2QZ analysis (a double power law with pure luminosity evolution characterized by a second-order polynomial in redshift), we find a faint-end slope of ß= -1.78 ± 0.03 if we allow all of the parameters to vary, and = -1.45 ± 0.03 if we allow only the faint-end slope and normalization to vary (holding all other parameters equal to the final 2QZ values). Over the magnitude range covered by the 2SLAQ survey, our maximum-likelihood fit to the data yields 32 per cent more quasars than the final 2QZ parametrization, but is not inconsistent with other g > 21 deep surveys for quasars. The 2SLAQ data exhibit no well-defined 'break' in the number counts or luminosity function, but do clearly flatten with increasing magnitude. Finally, we find that the shape of the quasar luminosity function derived from 2SLAQ is in good agreement with that derived from Type I quasars found in hard X-ray surveys.

Original languageEnglish (US)
Pages (from-to)839-852
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Volume360
Issue number3
DOIs
StatePublished - Jul 1 2005

Fingerprint

quasars
luminosity
telescopes
x rays

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Richards, G. T., Croom, S. M., Anderson, S. F., Bland-Hawthorn, J., Boyle, B. J., De Propris, R., ... York, D. G. (2005). The 2dF-SDSS LRG and QSO (2SLAQ) Survey: The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85. Monthly Notices of the Royal Astronomical Society, 360(3), 839-852. https://doi.org/10.1111/j.1365-2966.2005.09096.x
Richards, Gordon T. ; Croom, Scott M. ; Anderson, Scott F. ; Bland-Hawthorn, Joss ; Boyle, Brian J. ; De Propris, Roberto ; Drinkwater, Michael J. ; Fan, Xiaohui ; Gunn, James E. ; Ivezić, Željko ; Jester, Sebastian ; Loveday, Jon ; Meiksin, Avery ; Miller, Lance ; Myers, Adam ; Nichol, Robert C. ; Outram, Phil J. ; Pimbblet, Kevin A. ; Roseboom, Isaac G. ; Ross, Nie ; Schneider, Donald P. ; Shanks, Tom ; Sharp, Robert G. ; Stoughton, Chris ; Strauss, Michael A. ; Szalay, Alexander S. ; Vanden Berk, Daniel E. ; York, Donald G. / The 2dF-SDSS LRG and QSO (2SLAQ) Survey : The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85. In: Monthly Notices of the Royal Astronomical Society. 2005 ; Vol. 360, No. 3. pp. 839-852.
@article{a553899b430442178acd97333dcd3d57,
title = "The 2dF-SDSS LRG and QSO (2SLAQ) Survey: The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85",
abstract = "We have used the Two-Degree Field (2dF) instrument on the Anglo-Australian Telescope (AAT) to obtain redshifts of a sample of z < 3 and 18.0 < g < 21.85 quasars selected from Sloan Digital Sky Survey (SDSS) imaging. These data are part of a larger joint programme between the SDSS and 2dF communities to obtain spectra of faint quasars and luminous red galaxies, namely the 2dF-SDSS LRG and QSO (2SLAQ) Survey. We describe the quasar selection algorithm and present the resulting number counts and luminosity function of 5645 quasars in 105.7 deg 2. The bright-end number counts and luminosity functions agree well with determinations from the 2dF QSO Redshift Survey (2QZ) data to g ∼ 20.2. However, at the faint end, the 2SLAQ number counts and luminosity functions are steeper (i.e. require more faint quasars) than the final 2QZ results from Croom et al., but are consistent with the preliminary 2QZ results from Boyle et al. Using the functional form adopted for the 2QZ analysis (a double power law with pure luminosity evolution characterized by a second-order polynomial in redshift), we find a faint-end slope of {\ss}= -1.78 ± 0.03 if we allow all of the parameters to vary, and = -1.45 ± 0.03 if we allow only the faint-end slope and normalization to vary (holding all other parameters equal to the final 2QZ values). Over the magnitude range covered by the 2SLAQ survey, our maximum-likelihood fit to the data yields 32 per cent more quasars than the final 2QZ parametrization, but is not inconsistent with other g > 21 deep surveys for quasars. The 2SLAQ data exhibit no well-defined 'break' in the number counts or luminosity function, but do clearly flatten with increasing magnitude. Finally, we find that the shape of the quasar luminosity function derived from 2SLAQ is in good agreement with that derived from Type I quasars found in hard X-ray surveys.",
author = "Richards, {Gordon T.} and Croom, {Scott M.} and Anderson, {Scott F.} and Joss Bland-Hawthorn and Boyle, {Brian J.} and {De Propris}, Roberto and Drinkwater, {Michael J.} and Xiaohui Fan and Gunn, {James E.} and Željko Ivezić and Sebastian Jester and Jon Loveday and Avery Meiksin and Lance Miller and Adam Myers and Nichol, {Robert C.} and Outram, {Phil J.} and Pimbblet, {Kevin A.} and Roseboom, {Isaac G.} and Nie Ross and Schneider, {Donald P.} and Tom Shanks and Sharp, {Robert G.} and Chris Stoughton and Strauss, {Michael A.} and Szalay, {Alexander S.} and {Vanden Berk}, {Daniel E.} and York, {Donald G.}",
year = "2005",
month = "7",
day = "1",
doi = "10.1111/j.1365-2966.2005.09096.x",
language = "English (US)",
volume = "360",
pages = "839--852",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "3",

}

Richards, GT, Croom, SM, Anderson, SF, Bland-Hawthorn, J, Boyle, BJ, De Propris, R, Drinkwater, MJ, Fan, X, Gunn, JE, Ivezić, Ž, Jester, S, Loveday, J, Meiksin, A, Miller, L, Myers, A, Nichol, RC, Outram, PJ, Pimbblet, KA, Roseboom, IG, Ross, N, Schneider, DP, Shanks, T, Sharp, RG, Stoughton, C, Strauss, MA, Szalay, AS, Vanden Berk, DE & York, DG 2005, 'The 2dF-SDSS LRG and QSO (2SLAQ) Survey: The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85', Monthly Notices of the Royal Astronomical Society, vol. 360, no. 3, pp. 839-852. https://doi.org/10.1111/j.1365-2966.2005.09096.x

The 2dF-SDSS LRG and QSO (2SLAQ) Survey : The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85. / Richards, Gordon T.; Croom, Scott M.; Anderson, Scott F.; Bland-Hawthorn, Joss; Boyle, Brian J.; De Propris, Roberto; Drinkwater, Michael J.; Fan, Xiaohui; Gunn, James E.; Ivezić, Željko; Jester, Sebastian; Loveday, Jon; Meiksin, Avery; Miller, Lance; Myers, Adam; Nichol, Robert C.; Outram, Phil J.; Pimbblet, Kevin A.; Roseboom, Isaac G.; Ross, Nie; Schneider, Donald P.; Shanks, Tom; Sharp, Robert G.; Stoughton, Chris; Strauss, Michael A.; Szalay, Alexander S.; Vanden Berk, Daniel E.; York, Donald G.

In: Monthly Notices of the Royal Astronomical Society, Vol. 360, No. 3, 01.07.2005, p. 839-852.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The 2dF-SDSS LRG and QSO (2SLAQ) Survey

T2 - The z < 2.1 quasar luminosity function from 5645 quasars to g = 21.85

AU - Richards, Gordon T.

AU - Croom, Scott M.

AU - Anderson, Scott F.

AU - Bland-Hawthorn, Joss

AU - Boyle, Brian J.

AU - De Propris, Roberto

AU - Drinkwater, Michael J.

AU - Fan, Xiaohui

AU - Gunn, James E.

AU - Ivezić, Željko

AU - Jester, Sebastian

AU - Loveday, Jon

AU - Meiksin, Avery

AU - Miller, Lance

AU - Myers, Adam

AU - Nichol, Robert C.

AU - Outram, Phil J.

AU - Pimbblet, Kevin A.

AU - Roseboom, Isaac G.

AU - Ross, Nie

AU - Schneider, Donald P.

AU - Shanks, Tom

AU - Sharp, Robert G.

AU - Stoughton, Chris

AU - Strauss, Michael A.

AU - Szalay, Alexander S.

AU - Vanden Berk, Daniel E.

AU - York, Donald G.

PY - 2005/7/1

Y1 - 2005/7/1

N2 - We have used the Two-Degree Field (2dF) instrument on the Anglo-Australian Telescope (AAT) to obtain redshifts of a sample of z < 3 and 18.0 < g < 21.85 quasars selected from Sloan Digital Sky Survey (SDSS) imaging. These data are part of a larger joint programme between the SDSS and 2dF communities to obtain spectra of faint quasars and luminous red galaxies, namely the 2dF-SDSS LRG and QSO (2SLAQ) Survey. We describe the quasar selection algorithm and present the resulting number counts and luminosity function of 5645 quasars in 105.7 deg 2. The bright-end number counts and luminosity functions agree well with determinations from the 2dF QSO Redshift Survey (2QZ) data to g ∼ 20.2. However, at the faint end, the 2SLAQ number counts and luminosity functions are steeper (i.e. require more faint quasars) than the final 2QZ results from Croom et al., but are consistent with the preliminary 2QZ results from Boyle et al. Using the functional form adopted for the 2QZ analysis (a double power law with pure luminosity evolution characterized by a second-order polynomial in redshift), we find a faint-end slope of ß= -1.78 ± 0.03 if we allow all of the parameters to vary, and = -1.45 ± 0.03 if we allow only the faint-end slope and normalization to vary (holding all other parameters equal to the final 2QZ values). Over the magnitude range covered by the 2SLAQ survey, our maximum-likelihood fit to the data yields 32 per cent more quasars than the final 2QZ parametrization, but is not inconsistent with other g > 21 deep surveys for quasars. The 2SLAQ data exhibit no well-defined 'break' in the number counts or luminosity function, but do clearly flatten with increasing magnitude. Finally, we find that the shape of the quasar luminosity function derived from 2SLAQ is in good agreement with that derived from Type I quasars found in hard X-ray surveys.

AB - We have used the Two-Degree Field (2dF) instrument on the Anglo-Australian Telescope (AAT) to obtain redshifts of a sample of z < 3 and 18.0 < g < 21.85 quasars selected from Sloan Digital Sky Survey (SDSS) imaging. These data are part of a larger joint programme between the SDSS and 2dF communities to obtain spectra of faint quasars and luminous red galaxies, namely the 2dF-SDSS LRG and QSO (2SLAQ) Survey. We describe the quasar selection algorithm and present the resulting number counts and luminosity function of 5645 quasars in 105.7 deg 2. The bright-end number counts and luminosity functions agree well with determinations from the 2dF QSO Redshift Survey (2QZ) data to g ∼ 20.2. However, at the faint end, the 2SLAQ number counts and luminosity functions are steeper (i.e. require more faint quasars) than the final 2QZ results from Croom et al., but are consistent with the preliminary 2QZ results from Boyle et al. Using the functional form adopted for the 2QZ analysis (a double power law with pure luminosity evolution characterized by a second-order polynomial in redshift), we find a faint-end slope of ß= -1.78 ± 0.03 if we allow all of the parameters to vary, and = -1.45 ± 0.03 if we allow only the faint-end slope and normalization to vary (holding all other parameters equal to the final 2QZ values). Over the magnitude range covered by the 2SLAQ survey, our maximum-likelihood fit to the data yields 32 per cent more quasars than the final 2QZ parametrization, but is not inconsistent with other g > 21 deep surveys for quasars. The 2SLAQ data exhibit no well-defined 'break' in the number counts or luminosity function, but do clearly flatten with increasing magnitude. Finally, we find that the shape of the quasar luminosity function derived from 2SLAQ is in good agreement with that derived from Type I quasars found in hard X-ray surveys.

UR - http://www.scopus.com/inward/record.url?scp=22144451836&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=22144451836&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2966.2005.09096.x

DO - 10.1111/j.1365-2966.2005.09096.x

M3 - Article

VL - 360

SP - 839

EP - 852

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 3

ER -