The emergence of a neutral wind region in the orbital plane of symbiotic binaries during their outbursts

Abstract

Accretion of mass onto a white dwarf (WD) in a binary system can lead to stellar explosions. If a WD accretes from stellar wind of a distant evolved giant in a symbiotic binary, it can undergo occasional outbursts in which it brightens by several magnitudes, produces a low- and high-velocity mass-outflow, and, in some cases, ejects bipolar jets. In this paper, we complement the current picture of these outbursts by the transient emergence of a neutral region in the orbital plane of symbiotic binaries consisting of wind from the giant. We prove its presence by determining H${}^0$ column densities ($N_{\mathrm{H}}$) in the direction of the WD and at any orbital phase of the binary by modeling the continuum depression around the Ly$\alpha$ line caused by Rayleigh scattering on atomic hydrogen for all suitable objects, i.e., eclipsing symbiotic binaries, for which a well-defined ultraviolet spectrum from an outburst is available. The $N_{\mathrm{H}}$ values follow a common course along the orbit with a minimum and maximum of a few times $10^{22}$ and $10^{24}$ cm${}^{-2}$ around the superior and inferior conjunction of the giant, respectively. Its asymmetry implies an asymmetric density distribution of the wind from the giant in the orbital plane with respect to the binary axis. The neutral wind is observable in the orbital plane due to the formation of a dense disk-like structure around the WD during outbursts, which blocks ionizing radiation from the central burning WD in the orbital plane.

arXiv comment10 pages, 2 figures, 1 table, and 7 appendices with 5 figures and 4 tables on the next 15 pages. Accepted for The Astronomical Journal

References in corpus (31)

• A catalogue of symbiotic stars
• Binary orbits as the driver of gamma-ray emission and mass ejection in classical novae
• Disentangling the composite continuum of symbiotic binaries I. S-type systems
• A Nova Outburst Powered by Shocks
• Broad H-alpha wings from the optically thin stellar wind of the hot components in symbiotic binaries
• Revisiting the archetypical wind accretor Vela X-1 in depth -- A case study of a well-known X-ray binary and the limits of our knowledge
• Wind morphology around cool evolved stars in binaries: the case of slowly accelerating oxygen-rich outflows
• Neutron star masses from hydrodynamical effects in obscured sgHMXBs
• Structure of the hot object in the symbiotic prototype Z And during its 2000-03 active phase
• First Resolved Images of the Mira AB Symbiotic Binary at Centimeter Wavelengths
• The spectroscopic orbits and the geometrical configuration of the symbiotic binary AR Pavonis
• AGB winds in interacting binary stars
• New outburst of the symbiotic nova AG Peg after 165 years
• Evolution of the Symbiotic Nova PU Vul -- Outbursting White Dwarf, Nebulae, and Pulsating Red Giant Companion
• Wind mass transfer in S-type symbiotic binaries II. Indication of wind focusing
• Recent photometry of symbiotic stars - XIII
• Formation of a disk structure in the symbiotic binary AX Per during its 2007-10 precursor-type activity
• Activity cycle of the giant star of Z Andromedae and its spin period
• Multi-periodic variations in the last 104 years light curve of the symbiotic star BF Cyg
• Formation of the Asymmetric Accretion Disk from Stellar Wind Accretion in an S-type Symbiotic Star
• AG Pegasi - now a classical symbiotic star in outburst?
• Wind mass transfer in S-type symbiotic binaries III. Confirmation of a wind focusing in EG Andromedae from the nebular [OIII]λ5007 line
• Ionization structure of hot components in symbiotic binaries during active phases
• Spectroscopic view on the outburst activity of the symbiotic binary AG Draconis
• The path to Z And-type outbursts: The case of V426 Sagittae (HBHA 1704-05)
• Multiwavelength modeling the SED of nova V339~Del: Stopping the wind and long-lasting super-Eddington luminosity with dust emission
• The peculiar light curve of the Symbiotic Star AX Per of the last 125 years
• Measuring the orbital inclination of Z Andromedae from Rayleigh scattering
• Wind asymmetry imprint in the UV light curves of the symbiotic binary SY Mus
• Spectrum of the Yellow Symbiotic Star LT Delphini before, during, and after the 2017 Outburst
• Spectroscopic and photometric observations of Symbiotic Nova PU Vul during 2009-2016

Cited by in corpus (2)

• Wind-mass transfer in S-type symbiotic binaries IV. Indication of high wind-mass-transfer efficiency from active phases
• Density asymmetry and wind velocities in the orbital plane of the symbiotic binary EG Andromedae