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Counts of quasars at faint magnitudes: a new complete sample*

Published online by Cambridge University Press:  19 July 2016

G. Zamorani ,
V. Zitelli  and
B. Marano
G. Zamorani
Affiliation:
Istituto di Radioastronomia, Via Irnerio 46, 40126 Bologna, Italy
V. Zitelli
Affiliation:
Dipartimento di Astronomia, Via Zamboni 33, 40126 Bologna, Italy
B. Marano
Affiliation:
Dipartimento di Astronomia, Via Zamboni 33, 40126 Bologna, Italy

Abstract

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We present results on a new sample of optically selected quasar candidates. The “standard” multicolor technique for selecting quasar candidates has been applied to all the objects brighter than J = 22.0 in a field of 0.69 square degrees. Additional candidates have been selected from a search on grism plates obtained in the same area. Spectroscopy for all the candidates brighter than J = 20.9 has provided a sample of 22 confirmed quasars. The redshift distribution of these objects is essentially flat from z = 0.6 up to z = 2.8. Three out of the eight quasars with redshift larger than two were selected from the grism plates and were missed by our color selection. This result, although based on a small number of objects, suggests that the luminosity functions computed in this redshift range from samples which are only color selected might have to be increased by a factor up to 1.5. On the other hand, these possible losses of the multicolor search technique are negligible (of the order of 15% only) for the estimates of the integral number counts at magnitudes of the order 20–21.

Type
I. Surveys
Information
Symposium - International Astronomical Union , Volume 119: Quasars , 1986 , pp. 33 - 36
Copyright
Copyright © Reidel 1986 

References

Boyle, B.J., Fong, R., Shanks, T., and Peterson, B.A. 1986, in Structure and Evolution of Active Galactic Nuclei, Giuricin, G., Mardirossian, F., Mezzetti, M., and Ramella, M. eds., (Dordrecht: Reidel).Google Scholar
Braccesi, A., Formiggini, L., and Gandolfi, E. 1970, Astr. Ap., 5, 264.Google Scholar
D'Odorico, S. 1986, This Volume., p.57.Google Scholar
Koo, D.C., and Kron, R.G. 1982, Astr. Ap., 105, 107.Google Scholar
Koo, D.C., Kron, R.G., and Cudworth, K.M. 1985, preprint.Google Scholar
Marano, B., Zamorani, G., and Zitelli, V. 1986, in Structure and Evolution of Active Galactic Nuclei, Giuricin, G., Mardirossian, F., Mezzetti, M., and Ramella, M. eds., (Dordrecht: Reidel), in press.Google Scholar
Marano, B., Zamorani, G., and Zitelli, V. 1985, Proceedings of the Convegno Nazionale ASTRONET 1984–1985, 1985, Mem. Soc. Astr. It., in press.Google Scholar
Marshall, H.L. 1985, Ap. J., 299, in press.Google Scholar
Marshall, H.L., Avni, Y., Braccesi, A., Huchra, J.P., Tananbaum, H., Zamorani, G., and Zitelli, V. 1984, Ap. J., 283, 50.Google Scholar
Mitchell, K.J., Warnock, A. III, and Usher, P.D. 1984, Ap. J. (Letters), 287, L3.CrossRefGoogle Scholar
Osmer, P.S. 1986, This Volume, p.447.Google Scholar
Schmidt, M., and Green, R.F. 1983, Ap. J., 269, 352.Google Scholar
Shanks, T., Boyle, B.J., Fong, R., and Peterson, B.A. 1986, This Volume, p.37.Google Scholar