Loss of mass by the symbiotic binary Z And during its outburst at the end of 2002 Nikolai Tomov, Mima Tomova & Dmitry Bisikalo
The Symbiotic System Z And • A normalM4.5 III giant • A white dwarf with Teff 105 K • A partly photoionized surrounding nebula Components: Active phases of Z And: After 1915, 1939, 1960, 1984 and 2000.
The light curve of Z And during its last active phase after 2000 The dots indicate the data of Skopal et al. 2002, 2004, Skopal & Pribulla 2006 and Skopal & Wolf 2006. The squares indicate our data.
The spectral energy distribution of Z And during quiescenceand at different epochs of its 2000 - 2003 active phase The points indicate the observed fluxes. The thin lines represent the continua of the system’s components. The circles represent the UBVRI fluxes of the giant. The thick line represents the resulting continuum. In the region of the BVRI photometric bands the resulting continuum is represented by crosses, placed only at their positions, since the giant does not radiate as a blackbody in this region and its continuum has not been known at the other wavelengths. Flux units are erg cm-2 s-1 A-1.
Parameters of the hot stellar and the nebular components Parameters of the cool giant R = 85(d/1.12 kpc)R ,Teff = 3400 K
The H line during the outburst in 2002 Flux in units erg cm-2 s-1 292.098x10-12 255.255x10-12 173.494x10-12
The data of the H line during the outburst in 2002 The fluxes are in units of 10-12 erg cm-2 s-1. The other quantities are in units of km s-1. The mass-loss rate on November 12, 2002: Mdot = 1.9510-7 (d/1.12 kpc)3/2 M yr-1
The data of the HeII l 4686 line during the outburst in 2002 The fluxes are in units of 10-12 erg cm-2 s-1. The other quantities are in units of km s-1. The mass-loss rate on November 12, 2002: Mdot = 1.7410-7 (d/1.12 kpc)3/2 M yr-1
The mass-loss rate Mdot = 1.8 10-7 (d/1.12 kpc)3/2 M yr-1