Post-common envelope binaries from SDSS - XIV. The DR7 white dwarf-main sequence binary catalogue

TL;DR

This paper updates the SDSS white dwarf-main sequence binary catalogue, adding new systems, refining stellar parameters, and providing an online database, thereby enhancing the understanding of these binaries' properties and distributions.

Contribution

It presents an expanded, improved catalogue of WDMS binaries with new discoveries, refined parameters, and an accessible online database, highlighting the survey's success in identifying diverse systems.

Findings

Confirmed the presence of cooler, more massive white dwarfs in the sample.

Identified earlier spectral type companions than previous surveys.

Enhanced the statistical understanding of WDMS binary properties.

Abstract

We present an updated version of the spectroscopic white dwarf-main sequence (WDMS) binary catalogue from the Sloan Digital Sky Survey (SDSS). 395 new systems are serendipitous discoveries from the spectroscopic SDSSI/II Legacy targets. As part of SEGUE, we have carried out a dedicated and efficient (64 per cent success rate) search for WDMS binaries with a strong contribution of the companion star, which were underrepresented by all previous surveys, identifying 251 additional systems. In total, our catalogue contains 2248 WDMS binaries, and includes, where available, magnitudes from the GALEX All Sky Survey in the ultraviolet and from the UKIRT Infrared Sky Survey (UKIDSS) in the near-infrared. We also provide radial velocities of the companion stars, measured from the SDSS spectroscopy using the NaI8183.27,8194.81 absorption doublet and/or the Halpha emission. Using an updated version of our spectral decomposition/fitting technique we determine/update the white dwarf effective temperatures, surface gravities and masses, as well as the spectral type of the companion stars for the entire catalogue. Comparing the distributions of white dwarf mass, temperature, and companion spectral type, we confirm that our SEGUE survey project has been successful in identifying WDMS binaries with cooler and more massive white dwarfs, as well as earlier spectral types than found previously. Finally, we have developed a publicly available interactive on-line data base for spectroscopic SDSS WDMS binaries containing all available stellar parameters, radial velocities and magnitudes which we briefly describe.