Infrared spectroscopy of cataclysmic variables - II. Intermediate polars

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.

7 pages, 2 figures

Cited by in corpus (12)

• Infrared Properties of Cataclysmic Variables from 2MASS: Results from the 2nd Incremental Data Release
• Infrared spectroscopy of cataclysmic variables: III. Dwarf novae below the period gap and novalike variables
• High-resolution spectroscopy of the intermediate polar EX Hydrae. I. Kinematic study and Roche tomography
• Optical/Infrared spectroscopy and photometry of the short period binary RX J1914+24
• HST/STIS Spectroscopy of the Intermediate Polar EX Hydrae
• Multi-wavelength spectrophotometry of EX Hydrae
• The Nature of the Faint Chandra X-ray Sources in the Galactic Centre
• X-ray Point Source Populations Constituting the Galactic Ridge X-ray Emission
• Stellar Variability in the Globular Cluster Terzan 5
• An Infrared Imaging Survey of the Faint Chandra Sources near the Galactic Centre
• Near-infrared spectroscopy of 20 new Chandra sources in the Norma Arm
• Near-Infrared Spectroscopy of Faint Discrete X-ray Point Sources Constituting the Galactic Ridge X-ray Emission