Open AccessThe 2dF QSO Redshift Survey – I. The optical luminosity function of quasi‐stellar objects
Author(s) -
Boyle B. J.,
Shanks T.,
Croom S. M.,
Smith R. J.,
Miller L.,
Loaring N.,
Heymans C.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03730.x
Subject(s) - qsos , physics , astrophysics , redshift , luminosity function , quasar , luminosity , redshift survey , astronomy , galaxy
We present a determination of the optical luminosity function of quasi‐stellar objects (QSOs) and its cosmological evolution with redshift for a sample of over 6000 QSOs identified primarily from the first observations of the 2dF QSO Redshift Survey (2QZ). For QSOs with −26< M B <−23 and 0.35< z <2.3, we find that pure luminosity evolution (PLE) models provide an acceptable fit to the observed redshift dependence of the luminosity function (LF). The LF is best fitted by a two‐power‐law function of the form Exponential luminosity evolution models, both as a function of look‐back time, and as a general second‐order polynomial, were found to provide acceptable fits to the data set comprising the 2QZ and the Large Bright Quasar Survey. Exponential evolution with look‐back time is preferred for q 0 =0.05, while the polynomial evolution model is preferred for q 0 =0.5. The shape and evolution of the LF at low redshifts ( z <0.5) and/or high luminosities, not currently well sampled by the 2QZ survey, may show departures from pure luminosity evolution, but the results presented here show that, over a significant range of redshift, PLE is a good description of QSO evolution.