AAVSO: American Association of Variable Star Observers

An Analysis of X-Ray Hardness Ratios between Asynchronous and Non-Asynchronous Polars

Volume 49 number 2 (2021)

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Eric Masington
Department of Physics and Astronomy, Texas Tech University, Lubbock, TX 79409; eric.masington@ttu.edu
Thomas J. Maccarone
Department of Physics and Astronomy, Texas Tech University, Lubbock, TX 79409; thomas.maccarone@ttu.edu
Liliana Rivera Sandoval
Department of Physics and Astronomy, Texas Tech University, Lubbock, TX 79409; and Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3, Canada; lriveras@ualberta.ca
Craig Heinke
Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3, Canada; heinke@ualberta.ca
Arash Bahramian
Department of Physics and Astronomy, Curtin University, Perth, Western Australia 6845, Australia; arash.bahramian@curtin.edu.au
Aarran W. Shaw
Department of Physics, University of Nevada, Reno, NV 89557; aarrans@unr.edu

Abstract

The subclass of magnetic Cataclysmic Variables (CV) known as asynchronous polars is still relatively poorly understood. An asynchronous polar is a polar in which the spin period of the white dwarf is either shorter or longer than the binary orbital period (typically within a few percent). The asynchronous polars have been disproportionately detected in soft gamma-ray observations, leading us to consider the possibility that they have intrinsically harder x-ray spectra. We compared standard and asynchronous polars in order to examine the relationship between a CV’s synchronization status and its spectral shape. Using the entire sample of asynchronous polars, we find that the asynchronous polars may, indeed, have harder spectra, but that the result is not statistically significant.