Astron. Astrophys. 358, 77-87 (2000)

The Hamburg/ESO survey for bright QSOs

III. A large flux-limited sample of QSOs ^* **

L. Wisotzki, N. Christlieb, N. Bade, V. Beckmann, T. Köhler, C. Vanelle and D. Reimers

Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany (lwisotzki@hs.uni-hamburg.de)

Received 3 November 1999 / Accepted 18 February 2000

Abstract

We present a new sample of 415 bright QSOs and Seyfert 1 nuclei drawn from the Hamburg/ESO survey (HES). The sample is spectroscopically 99% complete and well-defined in terms of flux and redshift limits. Optical magnitudes are in the interval , redshifts range within . More than 50% of the objects in the sample are new discoveries. We describe the selection techniques and discuss sample completeness and potential selection effects. There is no evidence for redshift-dependent variations of completeness; in particular, low-redshift QSOs - notoriously missed by other optical surveys - are abundant in this sample, since no discrimination against extended sources is imposed. For the same reason, the HES is not biased against QSOs multiply imaged due to gravitational lensing. The sample forms the largest homogeneous set of bright QSOs currently in existence, useful for a variety of statistical studies. We have redetermined the bright part of the optical quasar number-magnitude relation. We confirm that the Palomar-Green survey is significantly incomplete, but that its degree of incompleteness has recently been overestimated.

Key words: galaxies: quasars: general galaxies: photometry galaxies: Seyfert cosmology: observations surveys

* Based on observations made at the European Southern Observatory, La Silla, Chile
** Table A.1 and B.1 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr

Send offprint requests to: L. Wisotzki

© European Southern Observatory (ESO) 2000

Online publication: June 26, 2000

helpdesk.link@springer.de