An unstable central disk in the superluminal black-hole X-ray binary GRS 1915+105

• Autores: Belloni, Tomaso; Méndez, Mariano; King, Andrew J.; van der Klis, M.; van Paradijs, J.
• Año de publicación: 1997
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ciencias Astronómicas; Physics; X-ray binary; Radiation; Solar mass; Instability; Accretion (astrophysics); Astrophysics; Spectral line; Superluminal motion; Black hole; Astronomy; Stars; Proportional counter
• Institución: Universidad Nacional de La Plata

We have analyzed the X-ray spectra of the microquasar GRS 1915+105, as observed with the PCA on the Rossi XTE, during periods of stable weak emission, outbursts and rapid flaring. We find that the complicated X-ray intensity curve of this source can be described by the rapid removal and replenishment of matter forming the inner part of an optically thick accretion disk, probably caused by a thermal-viscous instability analogous to that operating in dwarf novae, but here driven by the Lightman-Eardley instability. We find that the mass accretion rate in quiescence is 10^-6 solar masses per year. Only a small fraction of the energy liberated by accretion is emitted as radiation. We suggest that most of this energy is advected into the black hole in the high-viscosity state of the outburst cycle.
Facultad de Ciencias Astronómicas y Geofísicas