VV Pup in a low state: secondary-star irradiation or stellar activity?

Abstract

Aims. Emission lines in polars show complex profiles with multiple components that are typically ascribed to the accretion stream, threading region, accretion spot, and the irradiated secondary-star. In low-state polars the fractional contribution by the accretion stream, and the accretion spot is greatly reduced offering an opportunity to study the effect of the secondary-star irradiation or stellar activity. We observed VV Pup during an exceptional low-state to study and constrain the properties of the line-forming regions and to search for evidence of chromospheric activity and/or irradiation. Methods. We obtained phase-resolved optical spectra at the ESO VLT+FORS1 with the aim of analyzing the emission line profile and radial velocity as a function of the orbital period. We also tailored irradiated secondary-star models to compare the predicted and the observed emission lines and to establish the nature of the line-forming regions. Results. Our observations and data analysis, when combined with models of the irradiated secondary-star, show that, while the weak low ionization metal lines (FeI and MgI) may be consistent with irradiation processes, the dominant Balmer H emission lines, as well as NaI and HeI, cannot be reproduced by the irradiated secondary-star models. We favor the secondary-star chromospheric activity as the main forming region and cause of the observed H, NaI, and He emission lines, though a threading region very close to the L1 point cannot be excluded.

10 pages, 9 figures, in press on A&A

References in corpus (12)

• Activity and Kinematics of Ultracool Dwarfs Including An Amazing Flare Observation
• Far-ultraviolet Spectroscopy of Magnetic Cataclysmic Variables
• FUSE and HST/STIS far-ultraviolet observations of AM Herculis in an extended low state
• Model Atmospheres for Irradiated Stars in pre-Cataclysmic Variables
• Mass Determination and Detection of the Onset of Chromospheric Activity for the Sub-Stellar Object in EF Eridani
• The component masses of the cataclysmic variable V347 Puppis
• XMM-Newton observations of EF Eridani: the textbook example of low-accretion rate polars
• 1RXSJ062518.2+733433: A new intermediate polar
• Low State, Phase-Resolved IR Spectroscopy of VV Puppis
• Irregular Mass Transfer in the Polars VV Puppis and V393 Pavonis during the Low State
• A Photometric and Spectroscopic Study of the Cataclysmic Variable ST LMi during 2005-2006
• VV Pup in a low state: secondary-star irradiation or stellar activity?

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