5 papers · 1 filter
Observations of Spectral and Time Variabilities from MCG-2-58-22
Chul-Sung Choi, Tadayasu Dotani, Insu Yi +1
We present results from analysis of the X-ray archive data of MCG-2-58-22, acquired with ROSAT from 1991 to 1993 and with ASCA from 1993 to 1997. By analyzing light curves, we find…
Advection-Dominated Accetion Flows
Insu Yi
We review basic properties of advection-dominated accretion flows (ADAFs) and their applications to astrophysical systems ranging from Galactic binary systems to galactic nuclei. A…
Hard X-rays from Emission Line Galaxies and the X-ray Background: A Test for Advection Dominated Accretion with Radio Sources
Insu Yi, Stephen P. Boughn
Recent studies of the cosmic X-ray background (XRB) have suggested the possible existence of a population of relatively faint sources with hard X-ray spectra; however, the emission…
Mechanisms for the Outbursts of Soft X-ray Transients
J. -P. Lasota, R. Narayan, I. Yi
We show that the Keplerian thin disk in quiescent Soft X-ray Transients cannot extend down to the last stable orbit around the central black hole. We analyse the properties of the…
Advection-Dominated Accretion Model for Sagittarius A: Evidence for a $10^6\msun$ Black Hole at the Galactic Center
Ramesh Narayan, Insu Yi, Rohan Mahadevan
The enigmatic radio source Sagittarius A* at the centre of our Galaxy appears to be a low-luminosity version of active galactic nuclei in other galaxies. By analogy with active gal…