Ionization structure of hot components in symbiotic binaries during active phases

Abstract

During active phases of symbiotic binaries, an optically thick medium in the form of a flared disk develops around their hot stars. During quiescent phases, this structure is not evident. We propose the formation of a flared neutral disk-like structure around the rotating white dwarf (WD) in symbiotic binaries. We applied the wind compression model and calculated the ionization boundaries in the compressed wind from the WD using the equation of photoionization equilibrium. During active phases, the compression of the enhanced wind from the rotating WD can form a neutral disk-like zone at the equatorial plane, while the remainder of the sphere above/below the disk is ionized. Calculated hydrogen column density throughout the neutral zone and the emission measure of the ionized fraction of the wind are consistent with those derived from observations. During quiescent phases, the neutral disk-like structure cannot be created because of insufficient mass loss rate. Formation of the neutral disk-like zone at the equatorial plane is connected with the enhanced wind from the rotating WD, observed during active phases of symbiotic binaries. This probably represents a common origin of warm pseudophotospheres, indicated in the spectrum of active symbiotic binaries with a high orbital inclination.

10 pages, 6 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (5)

• Broad H-alpha wings from the optically thin stellar wind of the hot components in symbiotic binaries
• Structure of the hot object in the symbiotic prototype Z And during its 2000-03 active phase
• The origin of the supersoft X-ray--optical/UV flux anticorrelation in the symbiotic binary AG Draconis
• Formation of a disk structure in the symbiotic binary AX Per during its 2007-10 precursor-type activity
• A Study of an Outburst in the Classical Symbiotic Star Z And in a Colliding-Wind Model

Cited by in corpus (9)

• Early evolution of the extraordinary Nova Del 2013 (V339 Del)
• New outburst of the symbiotic nova AG Peg after 165 years
• The path to Z And-type outbursts: The case of V426 Sagittae (HBHA 1704-05)
• Multiwavelength modelling the SED of supersoft X-ray sources. II. RS Ophiuchi: From the explosion to the SSS phase
• Repeated transient jets from a warped disk in the symbiotic prototype Z And: A link to the long-lasting active phase
• Multiwavelength modeling the SED of nova V339~Del: Stopping the wind and long-lasting super-Eddington luminosity with dust emission
• Wind-mass transfer in S-type symbiotic binaries IV. Indication of high wind-mass-transfer efficiency from active phases
• The emergence of a neutral wind region in the orbital plane of symbiotic binaries during their outbursts
• The applicability of the wind compression model