The probable role of cloudy wind structure in the X-ray emission of the binary HD 193793

A model with interacting two-phase winds, each consisting of rarified gas a nd dense, compact clouds, is proposed to explain the weakness of the variab ility of the X-ray emission of the binary system HD 193793. The flowing tog ether of the rarified components, collisions of clouds, and the motion of t he clouds in the rarified component of the other wind are considered. Compu tations of the interactions of the rarified components were carried out usi ng the method of Chernyi for standard, two-dimensional, gas-dynamical probl ems, taking into account differences in the ion and electron temperatures. Due to the adiabatic expansion of the rarified gas behind the shock front, the X-ray luminosity decreases at 1/r, where ris the distance between the s tars in the system. The gas in the dense clouds radiates, leading, on the c ontrary, to a gradual growth in their luminosity in the transition from per iastron to apoastron, approximately proportional to r(1/3). The joint actio n of these two factors could give rise to the observed nearly constant lumi nosity of the system at 2-5 and 2-6 keV. The contribution of the clouds exc eeds that of the rarified component by a substantial factor. (C) 2000 MAIK "Nauka/Interperiodica".