Accreting Magnetic White Dwarf Linking Pulsars and Polars in Cataclysmic Variables
A magnetic white dwarf accreting from a Roche-lobe-filling donor while rapidly spinning down can share properties of both non-accreting white dwarf pulsars (extreme optical linear polarization, fast pulsed emission, rapid spin-down) and accreting polars (ongoing accretion, cyclotron-dominated optical modulation, hard X-rays). Such a system is a short-lived evolutionary stage in which a fast-spinning magnetic white dwarf is en route to synchronizing with its orbit and becoming a polar. Gaia22ayj, with a 9.36-minute spin period and 40 percent linear polarization, is the prototype of this proposed missing link.
Draft version January 6, 2025 Typeset using LATEX twocolumn style in AASTeX63 A Link Between White
Gaia22ayj is an accreting magnetic white dwarf in a close binary, characterized here through six years of high-speed multiwavelength photometry, phase-resolved spectroscopy, and polarimetry. It pulse…