The Hamburg Quasar Survey

Spectral analysis of sdB stars from the Hamburg Quasar Survey⋆

Abstract. We present the results of a spectral analysis of a large sample of subdwarf B stars selected from followup observations of candidates from the Hamburg Quasar Survey. Fundamental parameters (effective temperature, gravity, and helium abundance) were determined by matching synthetic line profiles calculated from model atmospheres to all hydrogen and helium absorption lines present in th...

The Hamburg Quasar Monitoring Program ( HQM ) at

An analysis of DA white dwarfs from the Hamburg Quasar Survey

Follow-up spectroscopy of several hundred hot stars detected by the Hamburg Quasar Survey (HQS) has been carried out between 1989 and 1996. We present the analysis of 80 DA white dwarfs using model atmospheres and theoretical cooling tracks to derive the atmospheric parameters Teff and log g, masses and absolute magnitudes. The HQS turned out to be sensitive to the detection of hydrogen-rich wh...

Two Close–Separation Quasar–Quasar Pairs in the Large Bright Quasar Survey

We present photometric and spectroscopic observations of two close quasar– quasar pairs found in the Large Bright Quasar Survey (LBQS) (Hewett et al. 1995, AJ, 109, 1498). The two components of the 2153-2056 pair (z = 1.845, ∆θ = 7. 8, B = 17.9 and 21.3) have the same redshifts within the relatively large uncertainty, ∆vA−B = −1100±1500 km s, of the observations. The quasars are most likely spa...

Finding the First Stars: The Hamburg/ESO Objective Prism Survey

The Hamburg/ESO survey (HES; [4]) is an objective-prism survey for bright quasars based on IIIa-J plates taken with the ESO Schmidt telescope and its 4◦ prism. It covers the total southern extragalactic sky (δ <+2◦. 5; |b| & 30◦). All 380 Schmidt plates (effective area ∼ 7 000 square degrees) have been taken, and have been digitized and reduced in Hamburg. The spectral range of the HES plates i...