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Arti Joshi & Jeewan Chandra Pandey

Study of an asynchronously rotating polar CD Ind

(Volume 88 - Année 2019 — Actes de colloques — 2nd Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - October 2018 - Brussels, Belgium)
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Mots-clés : accrétion, binaires proches, binaires magnétiques, variables cataclysmiques, étoiles individuelles, rayons X

Abstract

We present X-ray and ultaviolet (UV) analyses of the magnetic cataclysmic variable CD Ind. The X-ray light curves obtained from different observations show a very chaotic and spectacular pattern. X-ray and UV variations occur at orbital periods of (124.0±0.4) and (112.3±0.4) min and spin periods of (119.4±0.4) and (109.8±0.3) min, respectively. The degree of asynchronism of CD Ind is calculated as ~ 2.2% and ~ 3.7% from the UV and X-ray data, respectively. The variable shape of the X-ray and UV light curves indicate that the geometry of accretion changes in every epoch of observations. A two-pole accretion mode geometry is also visible in the X-ray and UV light curves of CD Ind. This two-pole accretion geometry is supported by the presence of double humps or dips in their X-ray and UV light curves. The rotational modulations of UV data are also found to be anti-correlated with respect to the X-rays, revealing that the UV pulsations are not originating in the region of magnetically confined accretion flow. Unlike other magnetic CVs, a strong fluorescent Ni Kα emission line is detected for the first time in the X-ray spectra of CD Ind. The X-ray and UV variations of CD Ind support the view that this system belongs to the class of asynchronous polars.

Keywords : accretion, binaries, close, magnetic CV, cataclysmic variables, stars, individual, (CD Ind), X-rays

To cite this article

Arti Joshi & Jeewan Chandra Pandey, «Study of an asynchronously rotating polar CD Ind», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 88 - Année 2019, Actes de colloques, 2nd Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - October 2018 - Brussels, Belgium, 240 - 247 URL : https://popups.uliege.be/0037-9565/index.php?id=8883.

About: Arti Joshi

Aryabhatta Research Institute of observational sciencES, Manora Peak, Nainital 263 001, India,  arti@aries.res.inaartijoshiphysics@gmail.com

About: Jeewan Chandra Pandey

Aryabhatta Research Institute of observational sciencES, Manora Peak, Nainital 263 001, India