ON THE EVOLUTION OF ACCRETION RATES IN COMPACT OUTBURST SOURCES

Journal Article · Sat Feb 20 00:00:00 EST 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/710/2/L147; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301270

Mandal, Samir

Spectra in outburst sources are found to become soft in viscous timescales before going back to hard as in the pre-outburst phase. By using two component accretion disks we show that major characteristics of the spectral evolution can be reproduced. We find that the outburst is possibly caused by a sudden rise in viscosity which gradually converts the sub-Keplerian flow into a Keplerian flow. The decline of the viscosity reduces the Keplerian accretion rate, and the system goes back to hard states. We discuss the genesis of the characteristic shape of the hardness-intensity diagram and reproduce this for the well-known outburst source GRO J1655-40.

• OSTI ID: 21301270
• Journal Information: Astrophysical Journal Letters, Vol. 710, Issue 2; Other Information: DOI: 10.1088/2041-8205/710/2/L147; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ACCRETION DISKS
BLACK HOLES
HYDRODYNAMICS
NEUTRON STARS
NEUTRONS
SHOCK WAVES
STAR EVOLUTION