2 papers
astro-ph1997
Properties of Point Mass Lenses On A Regular Polygon and The Problem of Maximum Number of Images
S. Mao, A. O. Petters, H. J. Witt
We study the critical curves, caustics, and multiple imaging due to one of the simplest many-body gravitational lens configurations: equal-mass point masses on the vertices of a re…
astro-ph1996
Luminosity to the Eddington luminosity ratio in AGN
B. Czerny, H. J. Witt, P. T. Zycki
We discuss the optical/UV/Xray spectra of AGN within the frame of the corona model of Witt, Czerny and Zycki (1996). In this model both the disk and the corona accrete and release…