New findings supporting the presence of a thick disc and bipolar jets in the $\mathsf{\beta}$ Lyrae system

Abstract

Context. Understanding large-scale mass exchange in binaries also requires studies of complicated objects in the rapid phases of the process. β Lyr is one such object. Aims. Our goals were to analyse 52 photographic and 651 electronic spectra of β Lyr to obtain additional information about circumstellar matter and to investigate spectrophotometric information for the first time. Methods. Improved quadratic ephemeris was derived via orbital solution with the FOTEL program. The spectra were disentangled using the KOREL program. Spectrophotometric quantities of 15 stronger absorption lines of the primary were measured and corrected for the orbital continuum variations using the fluxes calculated from a fit of the light curves with the BINSYN program. Central intensities of the V and R peaks of the Hα emission line were measured and corrected for the orbital light changes using the R-band light curve numerically modelled with the program PERIOD04. Results. Disentangling of photographic and electronic spectra led to the detection of weak absorption lines originating from the pseudophotosphere of the accretion disc. This way, a rich line spectrum of the accretion disc, not limited to only two previously known Si ii 6347 and Si ii 6371 lines, was obtained. A projected rotational velocity of 180 km s −1 was estimated for the disc spectrum. Such a value agrees well with the assumption of the Keplerian rotation of the outer layers of the accretion disc. After the correction, a pronounced increase of the strength of all absorption lines around phases of the primary eclipse was found. We argue that this is due to additional absorption of the light of the primary in one of the jets and/or scattering envelope above the accretion disc of the gainer. The net intensity of the V peak of Hα shows no orbital variation, but a possible 271-d periodicity. The net intensity of the R peak shows mild orbital changes and a slow change over a cycle of about 2780 days. These results seem to support the earlier conclusion that the Hα emission originates in the jet-like structures. Conclusions. All new findings support the current picture that the circumstellar structures of β Lyr consist of a thick accretion disc, bipolar jets, and a scattering envelope above the disc.

A large Hαline forming region for the massive interacting binaries β Lyrae and υ Sagitarii

“…5 in (Harmanec et al 1996) or Fig. 12 in (Ak et al 2007). The difference mainly originates from a saturation effect of the photon-counting camera in the emission line.…”

“…The material possibly connected with the bipolar flow is also inferred by the resolved radio nebula observed around β Lyr (Umana et al 2000(Umana et al , 2002). An extensive spectroscopic and photometric study (Ak et al 2007) has given new support to the presence of a thick disk and bipolar jets in this system. The first resolved images of the eclipsing binary β Lyr were obtained from near-IR observations with the CHARA interferometer and the MIRC combiner (Zhao et al 2008).…”

“…The time variability of the photometry and the spectroscopic information from the line (flux, Doppler velocities) was extensively used in the past to recover the complex geometry of this system (Ak et al 2007, and references therein). This time monitoring was also performed using spectropolarimetry and provided interesting information that can be compared with the optical interferometry data, at least qualitatively (Lomax & Hoffman 2011, HNF98).…”

Time-resolved spectroscopy of BD+46°442: Gas streams and jet creation in a newly discovered evolved binary with a disk

“…The existence of jets has been strongly advocated based on other independent arguments in e.g., a β Lyr system (Harmanec 2002;Ak et al 2007), a proto-type of the massive Rocheoverflow binaries (of which W Ser is a sub-class). Jets have been invoked to explain bipolar planetary and proto-planetary nebulae (PPNe), including the Red Rectangle (Cohen et al 2004;Velázquez et al 2011).…”

Mass loss out of close binaries

“…Effective temperatures are from Harmanec (2002). We derived a mass transfer rate from the values ofṖ given by Simon (1999) and Ak et al (2007). Harmanec (2002) reveals a minimum temperature for a hot spot of 20 000 K. Linnell (2002) proposes that the kinetic energy of the mass transfer stream is converted into heat and radiation at a radius equal to half of the radius of the accretion disk.…”