The Nature and Origin of Hercules X-1's Light-curve Dips

ISBN-13: 9783659148866 / Angielski / Miękka / 2012 / 296 str.

Ciprian D. Igna; Denis A. Leahy

Opis

HZ Her/Her X-1 is one of the most popular low-mass X-ray binary star systems, which consists of a neutron star (Her X-1) and a post-main-sequence star (HZ Her). Her X-1 is one of the first two founding members of the accretion-powered X-ray pulsars class. Due to its large luminosity and low interstellar absorption Her X-1 remains one of the most studied pulsars. The system is characterized by a great wealth of phenomena including 1.24 s regular X-ray pulsations, 1.7-day orbital period eclipses, a superorbital X-ray intensity cycle of ~35 days, and a large number of highly variable X-ray absorption events coined light-curve dips by Riccardo Giacconi, one of the 2002 Physics Nobel Prize laureates and founder of X-ray Astronomy. Unlike the periodic X-ray flux modulations, the light-curve dips are not well understood despite more than 30 years of intense research work. We present here the largest and most recent record of Her X-1s light-curve dips, and propose a theoretical model that reproduces the timing of any of the observed light-curve dips. The model is based on a single dip production mechanism and explains most dip properties, including the famous marching dip effect.

O autorze

Dr. Igna obtained his PhD at the University of Calgary. His research interests cover a wide range, including NMR coupling phenomena, Radiotherapy, Imaging and X-ray binaries. Prof. Leahy received his PhD at the University of British Columbia. His research interests include X-ray astronomy, X-ray binaries and Supernova remnants. Prof. Leahy received his Ph.D. in Physics from the University of British Columbia in 1980, and continued his academic career at NASA's Marshall Space Flight Center and the University of Calgary. His research interests include X-ray astronomy, X-ray binaries and Supernova remnants.