The SDSS spectroscopic catalogue of white dwarf-main sequence binaries: new identifications from DR9-12

TL;DR

This paper updates the SDSS spectroscopic catalogue of white dwarf-main sequence binaries, adding new identifications and analyzing their stellar parameters, radial velocities, and orbital periods, resulting in the largest homogeneous sample to date.

Contribution

It provides the most extensive and homogeneous SDSS WDMS binary catalogue with new identifications and detailed stellar parameter analysis, including radial velocities and orbital period estimates.

Findings

Total WDMS binaries increased to 3294, with 646 new systems.

98 objects show radial velocity variations, 62 are newly identified.

Orbital periods estimated for three close binaries.

Abstract

We present an updated version of the spectroscopic catalogue of white dwarf-main sequence (WDMS) binaries from the Sloan Digital Sky Survey (SDSS). We identify 939 WDMS binaries within the data releases (DR) 9-12 of SDSS plus 40 objects from DR 1-8 that we missed in our previous works, 646 of which are new. The total number of spectroscopic SDSS WDMS binaries increases to 3294. This is by far the largest and most homogeneous sample of compact binaries currently available. We use a decomposition/fitting routine to derive the stellar parameters of all systems identified here (white dwarf effective temperatures, surface gravities and masses, and secondary star spectral types). The analysis of the corresponding stellar parameter distributions shows that the SDSS WDMS binary population is seriously affected by selection effects. We also measure the NaI 8183.27, 8194.81 absorption doublet and Halpha emission radial velocities (RV) from all SDSS WDMS binary spectra identified in this work. 98 objects are found to display RV variations, 62 of which are new. The RV data are sufficient enough to estimate the orbital periods of three close binaries.