Time delay between the optical and X-ray outbursts in the high mass X-ray transient A0535+26/HDE245770

Дата и время публикации : 2013-05-22T14:34:55Z

Авторы публикации и институты :
F. Giovannelli
G. S. Bisnovatyi-Kogan
A. S. Klepnev

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 30 pages, 15 figures, with correction in abstract
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE

Краткий обзор статьи: The optical behaviour of the Be star in the high mass X-ray transient A0535+26/HDE245770 shows that at the periastron typically there is an enhancement in the luminosity of order 0.02 to few tenths mag, and the X-ray outburst happens about 8 days after the periastron. We construct a quantitative model of this event, basing on the a nonstationary accretion disk behavior, connected with a high ellipticity of the orbital motion. The ephemeris used in this paper — JD$_{rm opt-outb}$ = JD$_0$(2,444,944) $pm$ n(111.0 $pm$ 0.4) days are derived from the orbital period of the system P$_{rm orb} = 111.0 pm 0.4$ days, determined by Priedhorsky & Terrell (1983), and from the optical flare of December 5, 1981 (Giovannelli et al., 1985) (here after 811205-E; E stands for the Event occurred at that date) that triggered the subsequent X-ray outburst of December 13, 1981 (Nagase et al., 1982) (here after 811213-E). We explain the observed time delay between the peaks of the optical and X-ray outbursts in this system by the time of radial motion of the matter in the accretion disk, after an increase of the mass flux in the vicinity of a periastral point in the binary. This time is determined by the turbulent viscosity, with the parameter $alpha=0.1-0.3$. The increase of the mass flux is a sort of flush that reaches the external part of the accretion disk around the neutron star, producing an enhancement in the optical luminosity. The consequent X-ray flare happens when the matter reaches the hot central parts of the accretion disk, and the neutron star surface.

Category: Physics