Previous abstract Next abstract
Session 6 - Evolution, Survey and Clusters of Galaxies.
Display session, Monday, June 10
The survey, a collaborative effort of Hamburg University Observatory, Germany and Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, is a project devoted to identification of bright (B\leq17.5) quasar candidates selected from the objective prism spectra taken with the Calar Alto Schmidt telescope. We present the results obtained in the course of the first year of the survey.
The quasar candidate search is made in two steps: first, objective prism spectra with a blue continuum are selected automatically, second, a classification of these spectra is made interactively on a TV screen. Spectra unambiguously identified as stars due to their absorption features are discarded. Follow-up spectroscopy of candidates classified as potential quasars, excluding known objects, is performed with the use of the FLWO Tillinghast 1.5-meter telescope with the FAST spectrograph. Candidates are observed at a rate of \sim100 objects per night.
In the first year of the survey we have completed follow-up spectroscopic observations of candidates in 40 fields (\sim1,200 deg^2), and work is in progress on about twice as many fields. As of March 1996, we have observed just over a thousand objects; there are more than a hundred of previously unknown quasars among them. The survey quasar detection rate (including already known objects) is of the order of \sim20%. As a byproduct, hundreds of other ``scientifically interesting'' objects, such as H II galaxies, hot stars or CVs, have been discovered. The survey rate of new such objects is very high, of the order of 67%.
Data on all newly discovered objects --- coordinates, finding chart, magnitude, prism and slit spectra in a computer-readable form, plus a ``summary page'' outlining all of the above --- will be accessible through WWW.
Program listing for Monday