Portal de Periódicos da CAPES

The 2dF QSO Redshift Survey -- I. The optical luminosity function of quasi-stellar objects

2000; Oxford University Press; Volume: 317; Issue: 4 Linguagem: Inglês

10.1046/j.1365-8711.2000.03730.x

1365-2966

B. J. Boyle, T. Shanks, S. M. Croom, R. J. Smith, L. Miller, N. S. Loaring, C. Heymans,

Astrophysics and Star Formation Studies

We present a determination of the optical QSO luminosity function 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. The luminosity function is best fit 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 with redshift, were found to provide acceptable fits to the dataset comprising the 2QZ and the Large Bright Quasar Survey. Exponential evolution with look-back time is prefered for q_0=0.05, while the polynomial evolution model is prefered 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 2dF QSO 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.