2017MNRAS.466..129J

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 He II λ4686 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) x N. We also recovered the white dwarf spin period of P_spin = 503.32(3) s that gives a P_spin/P_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 and 8 h (lower limits) reaching ∼1.3 mag 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 d ≃ 2.1 kpc and a 0.5-10.0 keV X-ray luminosity upper limit of 2.0 x 10³³ erg s^–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 that is optically accessible.