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INTRODUCTION

The surface density of bright QSOs (B < 17.0) is still very poorly known. The Palomar Green (PG) or Bright Quasar Survey (BQS) [23,53] covering an area of 10714 deg2 lead to the discovery of 69 QSOs brighter than MB = -24 ($H_{\rm o}$ = 50 kms-1Mpc-1) and B = 16.16 corresponding to 0.0064 deg-2. However, several authors [22,33,36,51,58] suggested that this survey could be incomplete by a factor 2 to 3.

The First Byurakan Survey (FBS), also known as the Markarian survey, was carried out in 1965-80 by Markarian et al. [40]. It is a slitless spectroscopic photographic survey carried out with the 40$^{\prime\prime}$ Schmidt telescope of the Byurakan Observatory. The 1.5$^\circ$ prism used gave a reciprocal dispersion of 1800 Åmm-1 at H$\gamma$. Each field is 4$^\circ$$\times$4$^\circ$ in size. The survey is about 17000 deg2 and is complete to about B = 16.5 mag. It has been used by Markarian and his collaborators to search for UV excess galaxies; 1500 have been found, including about 10% Seyfert galaxies and a few QSOs. It can also be used for finding UV excess or emission-line star-like objects. Such a program - the second part of the FBS - has been undertaken in 1987 [9,45]. Its main purpose is to take advantage of the large area covered to get a reliable estimate of the surface density for bright QSOs. The discovery of a number of planetary nebula nuclei, white dwarfs, cataclysmic variables (CVs) and other UV excess objects is also expected.


next up previous
Next: THE FBS SURVEY Up: ON THE NATURE OF SURVEY Previous: ON THE NATURE OF SURVEY

3/11/1999