Spectral study of MWC560. Parameters of the system, the hot source and the jets

Abstract

Results of spectroscopy of unusual symbiotic star MWC560 are presented. The data have been obtained from autumn 1990 to spring 1993. The high velocity absorption line profiles demonstrate their origin in a jet, directed closely to the line of sight. These absorptions are variable at a time-scale less than one day and with an amplitude of about 10%. The fast variability of the absorption line profiles at 3 hours have been observed. An evidence of the opposite (second) jet has been found. An estimates of the orbital inclination angle about 10 deg and the jets parameters have been derived. We have simulated the continuum spectrum from UV to IR in the two different states (high and low) of MWC560. The observed spectrum is formed in a M4-5III giant, a hot source and in an absorbing screen (the jet). The object luminousity 2 10^37 erg/s is mainly from the UV source, whose temperature and size are 20000 K and 4 10^11 cm. The hot source is probably a photosphere of a massive wind (2 10^-6 M of Sun/year) rising from inner area aroung the white dwarf. We suppose that both the wind and jets are accelerated in magnetic field of the white dwarf, which accretes the gas from the giant wind as a propeller. The gas flows in accretion disk and is expelled from that by the rotating magnetic field. A sectorial structure of the outflow (jets) is formed. A surface magnetic field strength on the white dwarf is 3 10^8 G < B < 3 10^9 G, its rotational period is from 10-20 minutes to 3 hours.