CTCV J2056-3014: An X-ray-faint Intermediate Polar Harboring An Extremely Fast-spinning White Dwarf

Abstract

We report on XMM-Newton X-ray observations that reveal CTCV J2056-3014 to be an unusual accretion-powered, intermediate polar (IP) system. It is a member of the class of X-ray-faint IPs whose space density remains unconstrained but potentially very high, with L${}_{x,0.3-12keV}$ of 1.8$\times$10${}^{31}$ erg s${}^{-1}$. We discovered a coherent 29.6s pulsation in X-rays that was also revealed in our reanalysis of published optical data, showing that the system harbors the fastest-spinning, securely known white dwarf (WD) so far. There is no substantial X-ray absorption in the system. Accretion occurs at a modest rate ($\sim$ 6$\times$10${}^{-12}$ M${}_{\odot }$ yr${}^{-1}$) in a tall shock above the WD, while the star seems to be spinning in equilibrium and to have low magnetic fields. Further studies of CTCV J2056-3014 potentially have broad implications on the origin of magnetic fields in WDs, on the population and evolution of magnetic cataclysmic variables, and also on the physics of matter around rapidly rotating magnetic WDs.

Accepted for publication in ApJL, 5 pages, 2 figures

References in corpus (11)

• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc
• A radio pulsing white dwarf binary star
• An ultra-massive fast-spinning white dwarf in a peculiar binary system
• Polarimetric evidence of a white dwarf pulsar in the binary system AR Scorpii
• Constraints on the space density of intermediate polars from the Swift-BAT survey
• Exploratory Spectroscopy of Magnetic Cataclysmic Variables Candidates and Other Variable Objects
• A young contracting white dwarf in the peculiar binary HD 49798/RX J0648.0--4418?
• DW Cancri in x-rays
• XMM-Newton and Swift observations of WZ Sge: spectral and timing analysis
• Photometry of some more neglected bright cataclysmic variables and candidates

Cited by in corpus (15)

• An Isolated White Dwarf with a 70 second Spin Period
• Found: a rapidly spinning white dwarf in LAMOST J024048.51+195226.9
• Gravitational wave in f(R) gravity: possible signature of sub- and super-Chandrasekhar limiting mass white dwarfs
• Radio and optical observations of the possible AE Aqr twin, LAMOST J024048.51+195226.9
• A faint companion around CrA-9: protoplanet or obscured binary?
• 8.9-hr Rotation in the Partly Burnt Runaway Stellar Remnant LP 40-365 (GD 492)
• Magnetically-gated accretion model: application to short bursts in the intermediate polar V1223 Sgr
• The interacting double white dwarf population with LISA; stochastic foreground and resolved sources
• Discovery of a young pre-intermediate polar
• Optical detection of the rapidly spinning white dwarf in V1460 Her
• 1RXH J082623.6-505741: a new long-period cataclysmic variable with an evolved donor and a low mass transfer rate
• Periodicity from X-ray sources within the inner Galactic disk
• Searching for cataclysmic variable stars in unidentified X-ray sources
• Search for pulsars with periods of more than two seconds at declinations from +21${}^o$ to +42${}^o$
• Prospects for the Observation of Continuous Gravitational Waves from Deformed Fast-spinning White Dwarfs