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Title: The ELM Survey. IX. A Complete Sample of Low-mass White Dwarf Binaries in the SDSS Footprint
Abstract We present the discovery of 17 double white dwarf (WD) binaries from our ongoing search for extremely low mass (ELM) < 0.3 M ⊙ WDs, objects that form from binary evolution. Gaia parallax provides a new means of target selection that we use to evaluate our original ELM Survey selection criteria. Cross-matching the Gaia and Sloan Digital Sky Survey (SDSS) catalogs, we identify an additional 36 ELM WD candidates with 17 < g < 19 mag and within the 3 σ uncertainties of our original color selection. The resulting discoveries imply the ELM Survey sample was 90% complete in the color range −0.4 < ( g − r ) 0 < −0.1 mag (approximately 9000 K < T eff < 22,000 K). Our observations complete the sample in the SDSS footprint. Two newly discovered binaries, J123950.370−204142.28 and J232208.733+210352.81, have orbital periods of 22.5 and 32 minutes, respectively, and are future Laser Interferometer Space Antenna gravitational-wave sources.  more » « less
Award ID(s):
1906379
PAR ID:
10458399
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
933
Issue:
1
ISSN:
0004-637X
Page Range / eLocation ID:
94
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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