Physics Seminar
  • FENS
  • Physics Seminar

You are here

Sabancı University Physics Seminar

Title: Jets in black-hole and neutron-star X-ray binaries

Speaker: Nick Kylafis, University of Crete 

Date/Time: April 13, 2016 Wednesday at 13:40

Place: Sabancı University, FENS G035


Jets have been observed from both neutron-star and black-hole X-ray binaries.  There are many similarities between the two and a few differences.  I will offer a physical explanation of the formation and destruction of jets from compact objects and I will discuss the similarities and differences in the two types.  The basic concept in the physical explanation is the Cosmic Battery, the mechanism that creates the required magnetic field for the jet ejection.  The Cosmic Battery operates efficiently in accretion flows consisting of an inner hot flow and an outer thin accretion disk independently of the nature of the compact object.  It is therefore natural to always expect a jet in the right part of a spectral hardness – luminosity diagram and to never expect a jet in the left part.  As a consequence, most of the phenomenology of an outburst can be explained with only one parameter, the mass accretion rate.

Short Bio:

Nikos Kylafis received his PhD in Theoretical Astrophysics at the University of Illinois at Urbana-Champaign (USA) in 1978. He was a postdoctoral fellow at Caltech (1979 - 1981) and at the Institute for Advanced Study, Princeton (1981 - 1984). Then, he was an Assistant Professor at Columbia University (1984 - 1985) before accepting an Assistant Professor position at the University of Crete in 1985. He was promoted to Associate Professor in 1989 and Professor in 1997. He served as Chairman of the Department of Physics from 1999 to 2003, as well as Dean of the School of Sciences from September 2008 to May 2013. Since 2012, he is a member of the Council of the University of Crete.

Interests: Theoretical Astrophysics with special interests in Production and Transfer of Radiation, Compact X-ray Sources, Spiral Galaxies, and Astrophysical MASERs.