The Spin-Period History of Intermediate Polars

Abstract

We report the detailed history of spin-period changes in five intermediate polars (DQ Herculis, AO Piscium, FO Aquarii, V1223 Sagittarii, and BG Canis Minoris) during the 30-60 years since their original discovery. Most are slowly spinning up, although there are sometimes years-long episodes of spin-down. This is supportive of the idea that the underlying magnetic white dwarfs are near spin equilibrium. In addition to the ~40 stars sharing many properties and defined by their strong, pulsed X-ray emission, there are a few rotating much faster (P<80 s), whose membership in the class is still in doubt -- and who are overdue for closer study.

arXiv commentPDF, 13 pages, 1 table, 2 figures; submitted, ApJ; more info at http://cbastro.org/

References in corpus (11)

• Observations of Accreting Pulsars
• X-ray Emissions from Accreting White Dwarfs: a Review
• The spin periods and magnetic moments of white dwarfs in magnetic cataclysmic variables
• BK Lyncis: The Oldest Old Nova?... And a Bellwether for Cataclysmic-Variable Evolution
• On the spin-up/spin-down transitions in accreting X-ray binaries
• An HST parallax of the distant cataclysmic variable V1223 Sgr, its system parameters, and accretion rate
• Orbital and spin variability of the Intermediate Polar BG CMi
• On the space density of X-ray selected cataclysmic variables
• Return of the King: Time-Series Photometry of FO Aquarii's Initial Recovery from its Unprecedented 2016 Low State
• DQ Herculis in Profile: Whole Earth Telescope Observations and Smoothed Particle Hydrodynamics Simulations
• BG CMi time keeping

Cited by in corpus (13)

• Measuring the masses of magnetic white dwarfs: A NuSTAR Legacy Survey
• CTCV J2056-3014: An X-ray-faint Intermediate Polar Harboring An Extremely Fast-spinning White Dwarf
• The Large Array Survey Telescope -- Science Goals
• Long-term photometric monitoring and spectroscopy of the white dwarf pulsar AR Scorpii
• An Improved Spin-Down Rate for the Proposed White-Dwarf Pulsar AR Scorpii
• Classifying IGR J18007-4146 as an intermediate polar using XMM and NuSTAR
• Magnetically-gated accretion model: application to short bursts in the intermediate polar V1223 Sgr
• Optical detection of the rapidly spinning white dwarf in V1460 Her
• Searching for Diamagnetic Blob Accretion in the 74 day K2 Observation of V2400 Ophiuchi
• Current and secular accretion rates of EX Hydrae
• Measuring the precise photometric period of the intermediate polar 1RXS J230645.0+550816 (1SWXRT J230642.7+550817) based on extensive photometry
• Investigating the low-flux states in six Intermediate Polars
• The Periodic Signals of Nova V1674 Herculis (2021)