Measuring the masses of magnetic white dwarfs: A NuSTAR Legacy Survey

Abstract

The hard X-ray spectrum of magnetic cataclysmic variables can be modelled to provide a measurement of white dwarf mass. This method is complementary to radial velocity measurements, which depend on the (typically rather uncertain) binary inclination. Here we present results from a Legacy Survey of 19 magnetic cataclysmic variables with NuSTAR. We fit accretion column models to their 20-78 keV spectra and derive the white dwarf masses, finding a weighted average ${\bar{M}}_{\mathrm{WD}}=0.77\pm 0.02$ $M_{\odot }$, with a standard deviation $\sigma =0.10$ $M_{\odot }$, when we include the masses derived from previous NuSTAR observations of seven additional magnetic cataclysmic variables. We find that the mass distribution of accreting magnetic white dwarfs is consistent with that of white dwarfs in non-magnetic cataclysmic variables. Both peak at a higher mass than the distributions of isolated white dwarfs and post-common-envelope binaries. We speculate as to why this might be the case, proposing that consequential angular momentum losses may play a role in accreting magnetic white dwarfs and/or that our knowledge of how the white dwarf mass changes over accretion-nova cycles may also be incomplete.

14 pages. 5 figures in main paper, 1 figure in appendix. Accepted for publication in MNRAS

References in corpus (14)

• Magnetic White Dwarfs
• Magnetic fields in isolated and interacting white dwarfs
• Monte Carlo simulations of post-common-envelope white dwarf + main sequence binaries: comparison with the SDSS DR7 observed sample
• Carbon-Oxygen Classical Novae are Galactic ${}^7$Li Producers as well as Potential Supernova Ia Progenitors
• Intermediate polars in the Swift/BAT survey: Spectra and white dwarf masses
• Hard X-ray Cataclysmic Variables
• Observational Signatures of SNIa Progenitors, as Predicted by Models
• White dwarf masses in cataclysmic variables
• The X-ray properties of the magnetic Cataclysmic Variable UU Col
• The Spin-Period History of Intermediate Polars
• Are white dwarf magnetic fields in close binaries generated during common-envelope evolution?
• Magnetically moderated outbursts of WZ Sagittae
• Constraining the accretion geometry of the intermediate polar EX Hya using NuSTAR, Swift and Chandra observations
• DW Cancri in x-rays

Cited by in corpus (23)

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• Classifying IGR J18007-4146 as an intermediate polar using XMM and NuSTAR
• Hitting a New Low: The Unique 28 h Cessation of Accretion in the TESS Light Curve of YY Dra (DO Dra)
• Discovery of periodicities in two highly variable intermediate polars towards the Galactic Center
• Breaking the degeneracy in magnetic cataclysmic variable X-ray spectral modeling using X-ray light curves
• Classifying IGR J15038-6021 as a magnetic CV with a massive white dwarf
• X-ray spectroscopy method of white dwarf mass determination in intermediate polars. External systematic uncertainties
• Unravelling optical and X-ray properties of the disc-dominated intermediate polar IGR J15094-6649
• X-ray confirmation of the intermediate polar IGR J16547-1916
• Broad Observational Perspectives Achieved by the Accreting White Dwarf Sciences in the XMM-Newton and Chandra Eras
• Dynamical mass of the white dwarf in XY Ari: a test for intermediate polar X-ray spectral models
• XMM-Newton and NuSTAR discovery of a likely IP candidate XMMU J173029.8-330920 in the Galactic Disk
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• X-ray emission mechanisms in accreting white dwarfs
• Indications of magnetic accretion in Swift J0826.2-7033
• Significant reflection and absorption effects in the X-ray emission of the Intermediate Polar IGR J17195-4100
• Investigating the low-flux states in six Intermediate Polars
• Classification of IGR J20084+3221 as an Intermediate Polar using X-ray and Optical Observations
• Revisiting the X-ray Emission of the Asynchronous Polar V1432 Aql
• Searching for Magnetic White Dwarfs in LAMOST DR10