The evolutionary state of short-period magnetic white dwarf binaries
Abstract
We present phase-resolved spectroscopy of two new short-period low accretion rate magnetic binaries, SDSS J125044.42+154957.3 (P_(orb)= 86 min) and SDSS J151415.65+074446.5 (P_(orb)= 89 min). Both systems were previously identified as magnetic white dwarfs from the Zeeman splitting of the Balmer absorption lines in their optical spectra. Their spectral energy distributions exhibit a large near-infrared excess, which we interpret as a combination of cyclotron emission and possibly a late-type companion star. No absorption features from the companion are seen in our optical spectra. We derive the orbital periods from a narrow, variable Hα emission line which we show to originate on the companion star. The high radial velocity amplitude measured in both systems suggests a high orbital inclination, but we find no evidence for eclipses in our data. The two new systems resemble the polar EF Eri in its prolonged low state and also SDSS J121209.31+013627.7, a known magnetic white dwarf plus possible brown dwarf binary, which was also recovered by our method.
Additional Information
© 2012 The Authors. Monthly Notices of the Royal Astronomical Society © 2012 RAS. Accepted 2012 March 21. Received 2012 March 19; in original form 2012 February 11. Article first published online: 23 Apr 2012. EB, BTG, TRM and CMC acknowledge support from the UK STFC in the form of a Rolling Grant. This paper is based on observations made with the European Southern Observatory's Very Large Telescope, as part of programme 086.D-0243B. We also acknowledge the use of the Sloan Digital Sky survey (SDSS; http://www.sdss.org) and the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS; http://www.ukidss.org). The SDSS is funded by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society and the Higher Education Funding Council for England.Attached Files
Published - Breedt2012p18744Mon_Not_R_Astron_Soc.pdf
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Additional details
- Eprint ID
- 32322
- Resolver ID
- CaltechAUTHORS:20120710-102328999
- STFC (UK)
- 086.D-0243B
- European Southern Observatory
- Alfred P. Sloan Foundation
- NSF
- Department of Energy (DOE)
- NASA
- Japanese Monbukagakusho
- Max Planck Society
- Higher Education Funding Council for England
- Participating Institutions
- Created
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2012-07-10Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field