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Infrared spectroscopy of cataclysmic variables - II. Intermediate polars

V. S. Dhillon·T. R. Marsh·S. R. Duck·S. R. Rosen
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Abstract

We present infrared (0.97-2.45 micron) spectra of the intermediate polars PQ Gem (RE0751+14), BG CMi and EX Hya. The spectra show strong Paschen, Brackett and HeI emission lines from the accretion disc/stream. The infrared continua of PQ Gem and BG CMi can be represented by blackbodies of temperatures 4500 K and 5100 K, respectively, or by power-laws of the form f_nu \propto nu^(0.6,0.9), respectively, and show no evidence of secondary star features. The continuum of EX Hya is doiminated by water bands from the red-dwarf secondary star, which has a spectral type of ~M3. Despite showing circular polarization, PQ Gem and BG CMi show no evidence for cyclotron humps and hence we are unable to measure their magnetic field strengths; any cyclotron emission present must contribute less than ~3 per cent of the infrared continuum flux.

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V. S. Dhillon, T. R. Marsh, S. R. Duck, S. R. Rosen. 1996-09-06. Infrared spectroscopy of cataclysmic variables - II. Intermediate polars. https://doi.org/10.1093/mnras%2F285.1.95

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