We have measured the surface density of bright (B less-than-or-equal 16.5) UVX quasars in the recently completed Edinburgh quasar survey, and have found a higher density, by a factor of 3.4, than has previously been measured. The surface density of quasars brighter than B = 16.50 is 0.024 deg-2 in this survey, and the gradient of the differential log(number)-magnitude relation for quasars brighter than B = 17.7 has decreased from 0.98 to 0.78. Future work is expected to show that new models of the optical luminosity function for luminous quasars will need a smaller amount of cosmological evolution, more comparable to that seen at radio wavelengths.
Goldschmidt, P., Miller, L., LA FRANCA, F., Cristiani, S. (1992). THE HIGH SURFACE-DENSITY OF BRIGHT ULTRAVIOLET-EXCESS QUASARS. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 256(4), P65-P68.
THE HIGH SURFACE-DENSITY OF BRIGHT ULTRAVIOLET-EXCESS QUASARS
LA FRANCA, Fabio;
1992-01-01
Abstract
We have measured the surface density of bright (B less-than-or-equal 16.5) UVX quasars in the recently completed Edinburgh quasar survey, and have found a higher density, by a factor of 3.4, than has previously been measured. The surface density of quasars brighter than B = 16.50 is 0.024 deg-2 in this survey, and the gradient of the differential log(number)-magnitude relation for quasars brighter than B = 17.7 has decreased from 0.98 to 0.78. Future work is expected to show that new models of the optical luminosity function for luminous quasars will need a smaller amount of cosmological evolution, more comparable to that seen at radio wavelengths.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
