A search for intermediate-redshift quasars has been carried out with slitless spectroscopy in the central 21.07 deg2 of the SA 94, where the existence of a large database of objects for which slit spectroscopy was already available provided a valuable opportunity of testing the properties of our selection technique. Fifty candidates have been observed with slit spectroscopy, confirming 34 quasars and two H II galaxies. The completeness of this survey as a function of magnitude and redshift has been analysed, and an effective area of 16.9 deg2 has been evaluated. The estimated quasar surface density for QSOs with 1.8 < z < 3.2 and B < 19.4 is 1.4 +/- 0.3 deg-2, in agreement with other surveys in the literature. A brief analysis of the evolution of the volume density of quasars with - 27.35 < M(B) < - 28.5 is carried out, finding no evidence for a decrease at intermediate-large redshifts.
Cristiani, S., LA FRANCA, F., Barbieri, C., Clowes, R.g., Iovino, A. (1991). A COMPLETE QUASAR SAMPLE AT INTERMEDIATE REDSHIFT. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 250(3), 531-540.
A COMPLETE QUASAR SAMPLE AT INTERMEDIATE REDSHIFT
LA FRANCA, Fabio;
1991-01-01
Abstract
A search for intermediate-redshift quasars has been carried out with slitless spectroscopy in the central 21.07 deg2 of the SA 94, where the existence of a large database of objects for which slit spectroscopy was already available provided a valuable opportunity of testing the properties of our selection technique. Fifty candidates have been observed with slit spectroscopy, confirming 34 quasars and two H II galaxies. The completeness of this survey as a function of magnitude and redshift has been analysed, and an effective area of 16.9 deg2 has been evaluated. The estimated quasar surface density for QSOs with 1.8 < z < 3.2 and B < 19.4 is 1.4 +/- 0.3 deg-2, in agreement with other surveys in the literature. A brief analysis of the evolution of the volume density of quasars with - 27.35 < M(B) < - 28.5 is carried out, finding no evidence for a decrease at intermediate-large redshifts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
