Open AccessOn the iron Kα complex in magnetic cataclysmic variables
Author(s) -
Hellier Coel,
Mukai Koji
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07995.x
Subject(s) - physics , astrophysics , accretion (finance) , cataclysmic variable star , spectral line , doppler effect , line (geometry) , cyclotron , polar , emission spectrum , magnetic field , astronomy , stars , white dwarf , geometry , mathematics , quantum mechanics
We present a compilation of spectra of the iron Kα region in magnetic cataclysmic variables, using data from the Chandra High‐Energy Transmission Grating (HETG). The H‐like, He‐like and fluorescent components are clearly resolved, and there are hints of the structure within each component. The different shape of the He‐like component in AM Her might be related to greater cyclotron cooling in this star. A surprising absence of Doppler shifts in the H‐ and He‐like components implies that the X‐ray emission is predominantly from the denser, lower velocity base of the accretion columns. This absence will allow Astro‐E2 to resolve the structure in each component, leading to temperature diagnostics. We do not confirm the report that the H‐ and He‐like components of AO Psc are Compton‐broadened; however, we do detect a Compton‐downshifted shoulder to the fluorescent line of GK Per. Further, a Doppler‐shifted wing of this line arises in the high‐velocity, pre‐shock flow.