English

CXOGBS J174954.5-294335: A New Deeply-Eclipsing Intermediate Polar

Solar and Stellar Astrophysics 2017-01-17 v1 High Energy Astrophysical Phenomena

Abstract

We present the results of a photometric and spectroscopic analysis of the Galactic Bulge Survey X-ray source CXOGBS J174954.5-294335 (hereafter, referred to as CX19). CX19 is a long period, eclipsing intermediate polar type cataclysmic variable with broad, single-peaked Balmer and Paschen emission lines along with HeII λ4686\lambda4686 and Bowen blend emission features. With coverage of one full and two partial eclipses and archival photometry, we determine the ephemeris for CX19 to be HJD(eclipse) = 2455691.8581(5) + 0.358704(2)×\timesN. We also recovered the white dwarf spin period of Pspin_{\rm spin} = 503.32(3) seconds which gives a Pspin_{\rm spin}/Porb_{\rm orb} = 0.016(6), comparable to several confirmed, long period intermediate polars. CX19 also shows a clear X-ray eclipse in the 0.3-8.0 keV range observed with Chandra. Two optical outbursts were observed lasting between 6-8 hours (lower limits) reaching \sim1.3 mags in amplitude. The outbursts, both in duration and magnitude, the accretion disc dominated spectra and hard X-ray emission are reminiscent of the intermediate polar V1223 Sgr sharing many of the same characteristics. If we assume a main sequence companion, we estimate the donor to be an early G-type star and find a minimum distance of dd \approx 2.1 kpc and a 0.5-10.0 keV X-ray luminosity upper limit of 2.0 ×\times 1033^{33} erg s1^{-1}. Such an X-ray luminosity is consistent with a white dwarf accretor in a magnetic cataclysmic variable system. To date, CX19 is only the second deeply-eclipsing intermediate polar with X-ray eclipses and the first which is optically accessible.

Keywords

Cite

@article{arxiv.1612.01612,
  title  = {CXOGBS J174954.5-294335: A New Deeply-Eclipsing Intermediate Polar},
  author = {Christopher B. Johnson and M. A. P. Torres and R. I. Hynes and P. G. Jonker and C. Heinke and T. Maccarone and C. T. Britt and D. Steeghs and T. Wevers and Jianfeng Wu},
  journal= {arXiv preprint arXiv:1612.01612},
  year   = {2017}
}

Comments

Accepted for publication in MNRAS, 25 pages, 15 figures, 1 table