X-Ray Emission and Optical Polarization of V1432 Aquilae: An Asynchronous Polar

Abstract

A detailed analysis of X-ray data from ROSAT, ASCA, XMM and RXTE for the asynchronous polar V1432 Aql along with Stokes polarimetry data from SAAO, is presented. Power spectra from long-baseline ROSAT data show a spin period of 12150s along with several system related frequency components. However, the second harmonic of the spin period dominates power spectrum in the XMM data. For the optical circular polarization, the dominant period corresponds to half the spin period. The ROSAT data can be explained as due to accretion onto two hot spots that are not anti-podal. The variations seen in the optical polarization and the ASCA and XMM data suggest the presence of at least three accretion foot prints on the white dwarf surface. Two spectral models, a multi-temperature plasma and a photo-ionized plasma model, are used for spectral study. The RXTE PCA data are used to constrain the white dwarf mass to 1.2$\pm$0.1 M_odot using the multi-temperature plasma model. A strong soft X-ray excess (<0.8 keV) in the XMM MOS data is well modeled by a blackbody component having a temperature of 80-90 eV. The plasma emission lines seen at 6.7 and 7.0 keV are well fitted using the multi-temperature plasma model, however an additional Gaussian is needed for the 6.4 keV line. The multi-temperature plasma model requires a homogeneous absorber fully covering the source and a partial absorber covering 65% of the source. The photo-ionized plasma model, with a range of Fe column densities, gives a slightly better overall fit and fits all emission lines. The presence of a strong blackbody component, a spin period of 12150s, modulation of the 6.4 keV line flux with spin period, and a very hard X-ray component suggest that V1432 Aql is a polar with X-ray spectral properties similar to that of a soft intermediate polar.

arXiv comment46 pages, including 13 figures and 4 tables, To appear in The Astrophysical Journal, 20 May 2005 issue, vol. 625, Added Report-no and Journal-ref, no change in the text of the paper

References in corpus (15)

• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• Two Types of X-ray Spectra in Cataclysmic Variables
• Effects of Gravity on the Structure of Postshock Accretion Flows in Magnetic Cataclysmic Variables
• The energy balance in polars revisited
• Determining the mass of the accreting white dwarf in magnetic CVs using data
• X-ray and optical observations of 1RXS J154814.5-452845: a new intermediate polar with soft X-ray emission
• BeppoSAX observations of soft X-ray Intermediate Polars
• XMM-Newton observations of three short period polars: V347 Pav, GG Leo and EU UMa
• Time-Resolved HST Spectroscopy of Four Eclipsing Magnetic Cataclysmic Variables
• RX J2115-5840: confirmation of a new near-synchronous polar
• X-ray Variability of the Magnetic Cataclysmic Variable V1432 Aql and the Seyfert Galaxy NGC 6814
• Periodicities In The X-Ray Intensity Variations of TV Columbae: An Intermediate Polar
• X-ray Spectroscopy of the IP PQ Gem
• The near-synchronous polar V1432 Aql (RX J1940.1-1025): Accretion geometry and synchronization time scale
• An alternative model of the magnetic cataclysmic variable V1432 Aquilae (=RX J1940.1-1025)

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• Optical identification of X-ray source 1RXS J180431.1-273932 as a magnetic cataclysmic variable
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• A Far Ultraviolet Study of the Nova-like V794 Aquilae
• Radio detections of two unusual cataclysmic variables in the VLA Sky Survey
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• Study of magnetized accretion flow with variable $\Gamma$ equation of state
• Broad Observational Perspectives Achieved by the Accreting White Dwarf Sciences in the XMM-Newton and Chandra Eras
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