Suchergebnisse

GRS 1758–258 is the least studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10 keV flux when entering the thermally dominated soft state, rather than an increase.We present the spectral evolution of GRS 1758–258 from RXTE-PCA observations spanning a time of about 11 years from 1996 to 2007. During this time, seven dim soft states are detected. We also consider INTEGRAL monitoring observations of the source and compare the long-term behavior to that of the bright persistent black hole X-ray binary Cygnus X-1. We discuss the observed state transitions in the light of physical scenarios for black hole transitions.

G.Á-P. and J.T.-G. acknowledge the support through the Severo Ochoa Program from the Government of the Principality of Asturias (grants PA-20-PF-BP19-053 and PA-18-PF-BP17-126, respectively). P.A-G. acknowledges support from the European Research Council under Starting Grant 715496, 2DNANOPTICA. A.Y.N. acknowledges the Spanish Ministry of Science, Innovation and Universities (national project N° MAT201788358-C3-3-R) and the Basque Department of Education (grant PIBA-2020-1-0014). E.J.H. Lee acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities, through the "María de Maeztu" Programme for Units of Excellence in R&D (CEX2018-000805-M) and the Ramón y Cajal grant RYC-2015-17973 (.)