M. Sikora(1, 2), M.C. Begelman(2, 3), P. Coppi(2, 4), D. Proga(2) ((1) Nicolaus Copernicus Astronomical Center, Warsaw, (2) JILA, University of Colorado at Boulder, (3) also Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, (4) Department of Astronomy, Yale University)
