Bipolar ejection by the symbiotic binary system Z And during its 2006 outburst

High-resolution data in the region of the Hα line have been obtained at the time of light maximum and after it for the 2006 optical outburst of the symbiotic binary Z And. A blueshifted absorption component indicating an outflow velocity of about 1400 km s^-1, as well as additional emission components with similar velocities, situated on the two sides of the main peak of the line, were observed during that time. It is suggested that all of them are spectral signatures of bipolar outflow, observed for the first time in the optical spectrum of this binary. The emission measure and the mass of the nebular part of the streams have been estimated approximately, reaching values of up to about 6 × 10⁵⁷ cm^-3 and 8 × 10^-8M_solar.

Based on observations collected at the National Astronomical Observatory Rozhen, Bulgaria.

E-mail: tomov@astro.bas.bg