Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...438..623p&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 438, no. 2, p. 623-631
Astronomy and Astrophysics
Astronomy
188
Astronomical Models, Cosmology, Quasars, Stellar Evolution, Stellar Luminosity, Abundance, Extrapolation, Red Shift, Sky Surveys (Astronomy), Spatial Distribution, Stellar Magnitude
Scientific paper
We propose a new evolutionary model for the optical luminosity function of quasars. Our analytical model is derived from fits to the empirical luminosity function estimated by Hartwick and Schade and Warren, Hewett, and Osmer on the basis of more than 1200 quasars over the range of redshifts 0 approximately less than z approximately less than 4.5. We find that the evolution of quasars over this entire redshift range can be well fitted by a Gaussian distribution, while the shape of the luminosity function can be well fitted by either a double power law or an exponential L1/4 law. The predicted number counts of quasars, as a function of either apparent magnitude or redshift, are fully consistent with the observed ones. Our model indicates that the evolution of quasars reaches its maximum at z approximately = 2.8 and declines at higher redshifts. An extrapolation of the evolution to z approximately greater than 4.5 implies that quasars may have started their cosmic fireworks at zf approximately = 5.2-5.5. Forthcoming surveys of quasars at these redshifts will be critical to constrain the epoch of quasar formation. All the results we derived are based on observed quasars and are therefore subject to the bias of obscuration by dust in damped Ly alpha systems. Future surveys of these absorption systems at z approximately greater than 3 will also be important if the formation epoch of quasars is to be known unambiguously.
No associations
LandOfFree
The luminosity function of quasars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The luminosity function of quasars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The luminosity function of quasars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1819011