Fast variation of Cygnus X-1 and related sources

Abstract

view Abstract Citations (14) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Fast Variation of Cygnus X-1 and Related Sources Chagelishvili, G. D. ; Lominadze, J. G. ; Rogava, A. D. Abstract A new model is offered for explaining the millisecond variability of Cyg X-1 and related sources, based on the bimodal accretion model for Cyg X-1. In the region of the main energy, release action of the Parker instability leads to the formation of three to five (depending on concrete circumstances) oblong-shaped magnetic arcs within the whole azimuth. Those are the magnetic arcs which make up, consequently, an optically thin hot corona needed for explaining the 'low' state spectrum of Cyg X-1. Rapid rotation of the stretched magnetic arcs leads to fast variations of their lengths scales along the line of sight. Accordingly, the optical depth of each arc with respect to Thomson scattering, tau, will also vary, leading to the variations of spectral indices of arcs determined in terms of tau for the inverse Compton scattering. In its turn, it leads to rapid variations of photon count rates in the proper energy range. The described mechanism is effective when n = 3 (n is the number of arcs) but for n = 5 it is essentially weakened; i.e., in the latter case fast variations are actually absent. Publication: The Astrophysical Journal Pub Date: December 1989 DOI: 10.1086/168198 Bibcode: 1989ApJ...347.1100C Keywords: Accretion Disks; Stellar Radiation; Variable Stars; X Ray Binaries; Magnetohydrodynamics; Stellar Models; Stellar Rotation; Astrophysics; HYDROMAGNETICS; RADIATION MECHANISMS; STARS: ACCRETION; STARS: INDIVIDUAL CONSTELLATION NAME: CYGNUS X-1; STARS: VARIABLES; X-RAYS: BINARIES full text sources ADS | data products SIMBAD (4)