PREDNASAJUCI / LECTURER :

Natalia Shagatova

NAZOV / TITLE :

Confirmation of a wind focusing in EG Andromedae from the nebular [O iii] λ 5007 line

ABSTRAKT / ABSTRACT :

The distribution of the wind from the cool giants in symbiotic binaries
affects the efficiency of the mass transfer to their white dwarf companions.
The standard Bondi-Hoyle type of accretion does not provide sufficient
accretion rate to power high observed luminosities of hot components.
The deviation from spherical distribution of the wind from the donor
star can be the clue to this problem. For the D-type symbiotic systems
with Mira star donors, highly aspherical mass outflow, enhanced at the
orbital plane area, was confirmed by observations and numerical simulations.
However, for the majority of symbiotic stars, the S-type systems with red
giant branch donors, there is a lack of such indications.
Here, we present the analysis of orbital variations of fluxes and radial
velocities of H_alpha and [O iii] λ 5007 spectral lines of a quiet symbiotic
star EG Andromedae. The unexpected behaviour of the nebular [O iii] λ 5007
line revealed diluted material close to poles of the red giant companion
and provided independent confirmation of the wind focusing towards the orbital
plane in this system.