University of Leicester
MNRAS-2014-Baxter-3184-201.pdf (1.03 MB)

Component masses of young, wide, non-magnetic white dwarf binaries in the SDSS DR7

Download (1.03 MB)
journal contribution
posted on 2017-01-09, 15:33 authored by R. B. Baxter, P. D. Dobbie, Q. A. Parker, S. L. Casewell, N. Lodieu, M. R. Burleigh, K. A. Lawrie, B. Külebi, D. Koester, B. R. Holland
We present a spectroscopic component analysis of 18 candidate young, wide, non-magnetic, double-degenerate binaries identified from a search of the Sloan Digital Sky Survey Data Release 7 (DR7). All but two pairings are likely to be physical systems. We show SDSS J084952.47+471247.7 + SDSS J084952.87+471249.4 to be a wide DA+DB binary, only the second identified to date. Combining our measurements for the components of 16 new binaries with results for three similar, previously known systems within the DR7, we have constructed a mass distribution for the largest sample to date (38) of white dwarfs in young, wide, non-magnetic, double-degenerate pairings. This is broadly similar in form to that of the isolated field population with a substantial peak around M~0.6 Msun. We identify an excess of ultra-massive white dwarfs and attribute this to the primordial separation distribution of their progenitor systems peaking at relatively larger values and the greater expansion of their binary orbits during the final stages of stellar evolution. We exploit this mass distribution to probe the origins of unusual types of degenerates, confirming a mild preference for the progenitor systems of high-field-magnetic white dwarfs, at least within these binaries, to be associated with early-type stars. Additionally, we consider the 19 systems in the context of the stellar initial mass-final mass relation. None appear to be strongly discordant with current understanding of this relationship.


This work is based in part on observations made with the Gran Telescopio Canarias (GTC), operated on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The INT and the WHT are operated by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Based in part on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme numbers 084.D-1097 and 090.D-0140. Based in part on observations obtained as part of the VISTA Hemisphere Survey, ESO Progam, 179.A-2010 (PI: McMahon). This research was made possible through the use of the AAVSO Photometric All-Sky Survey (APASS), funded by the Robert Martin Ayers Sciences Fund. This research has made use of the Simbad database, operated at the Centre de Donn´ees Astronomiques de Strasbourg (CDS), and of NASA’s Astrophysics Data System Bibliographic Services (ADS). Funding for the SDSS and SDSS-II was provided by the Alfred P. Sloan Foundation, with Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS Web Site is SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. NL acknowledges support from the national program number AYA2010-19136 funded by the Spanish Ministry of Science and Innovation. NL is a Ram´on y Cajal fellow at the IAC (number 08-303-01-02). Balmer/Lyman lines in the DA models were calculated with the modified Stark broadening profiles of Tremblay & Bergeron (2009), kindly made available by the authors.



Monthly Notices of the Royal Astronomical Society (June 1, 2014) 440 (4): 3184-3201.

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy


  • VoR (Version of Record)

Published in

Monthly Notices of the Royal Astronomical Society (June 1


Oxford University Press (OUP), Royal Astronomical Society





Acceptance date


Available date


Publisher version



Usage metrics

    University of Leicester Publications


    No categories selected


    Ref. manager