X-Shooting EF Eridani: further evidence for a massive white dwarf and a sub-stellar secondary
Abstract
High resolution spectral observations of the polar EF Eridani obtained in a low state with X-Shooter revealed narrow emission lines from the irradiated secondary. The lines were most prominent in the near-IR Ca2-triplet, the more intensive Halpha line had additional emission likely originating from an accretion stream. The lines with a radial velocity amplitude, K2' = 385 +- 4 kmps, serve as tracer of the otherwise unseen companion. The mass function implies a massive white dwarf with Mwd > 0.65 Msun at 3sigma confidence, and a short distance to the binary, d ~ 111 pc (<145pc at 3sigma confidence). The spectral energy distribution from the UV to the IR together with the high mass ratio gives further strong evidence of EF Eri being a post period-minimum object with M2 < 0.06 Msun
Keywords
Cite
@article{arxiv.1003.1629,
title = {X-Shooting EF Eridani: further evidence for a massive white dwarf and a sub-stellar secondary},
author = {A. D. Schwope and L. Christensen},
journal= {arXiv preprint arXiv:1003.1629},
year = {2015}
}
Comments
Astron, Astrophys., in press