The Hamburg/ESO Survey: Concept and design in Overview

Scientific Goals

• compile samples of high-redshift (1.5 < z < 3.2), bright QSOs suited for high-resolution spectroscopy (e.g., for the ESO-VLT);
• provide targets for ultraviolet spectroscopy with HST;
• discover new gravitationally lensed systems;
• construct large flux-limited and bias-free samples of bright low-redshift QSOs and Seyferts for host galaxy studies;
• determine the local luminosity function of QSOs;
• study the evolution of the most luminous part of the QSO population.

Basic Properties

• ESO key programme since 1990;
• based on objective prism spectra taken with ESO Schmidt;
• Digitisation with Hamburg PDS microdensitometer;
• Magnitude range: 13 < B < 18;
• aims at complete coverage of southern extragalactic sky: 9000 deg² = 375 ESO fields.

More Properties

• Candidate selection with multitude of selection criteria
• Limiting magnitude: B < 18-18.5 (detection limit); B < 17-17.5 (completeness limit)
• Efficient removal of stellar contamination because of high spectral resolution: \sim 15 AA at H\gamma. (Spin-off: Many interesting stars discovered!)
• Success rate of 70 % for quasars in follow-up spectroscopy, without sacrifices in completeness.

Current status

• Plates exist for all fields.
• Plates for 345 ESO fields are digitised & reduced.
• Follow-up complete for 336 fields: \sim 1400 QSOs with B < 18 (\sim 700 newly discovered)
• New flux-limited sample of 415 QSOs with B < 17 in effective area of 3700 deg²
  (see here for the redshift histogram )
  $\rightarrow$ Largest existing sample of bright QSOs.
• Surface density of QSOs is consistent with or higher than in other surveys.
• Survey will be completed by mid-1999.

Last modified 21.01.1999 by L. Wisotzki