A walk through the different spectral states of low-mass X-ray binaries
PhD ceremony: Ms. B. Hiemstra, 14.30 uur, Aula Academiegebouw, Broerstraat 5, Groningen
Dissertation: A walk through the different spectral states of low-mass X-ray binaries
Promotor(s): prof. R.M. Méndez
Faculty: Mathematics and Natural Sciences
Low-mass X-ray binaries are systems in which a compact object, a neutron star or a black hole, accretes matter from a normal star that has a mass equal to, or less than that of our Sun. Mass accretion proceeds via a so-called accretion disc in which matter spirals inwards, sometimes down to a few kilometers from the compact object. Internal friction heats up the disc such that it radiates in X-rays. The disc and compact object are surrounded by a hot plasma, the so-called corona, which also radiates in X-rays and gamma-rays. While there is observational evidence (and theoretical expectations) of such a corona, the geometry and origin of the corona remains unclear. X-ray satellites allow us to study the radiation coming from the disc and corona, and hence to explore the compact objects and their close environment. In this thesis I study specific properties of the accretion process in low-mass X-ray binaries. Accretion proceeds in different ways and change with time, giving rise to the so-called spectral states. The geometry and temperature of the accretion disc and corona depend upon (and in fact define) these different states. By walking through various spectral states, this thesis highlights from an observational perspective a few particular aspects of the individual states, which are key for the general understanding of the accretion processes in low-mass X-ray binaries.
Last modified: | 13 March 2020 01.01 a.m. |
More news
-
23 April 2024
Nine MSCA Doctoral Network grants for FSE researchers
Nine researchers of the Faculty of Science and Engineering have received a Horizon Europe Marie Sklodowska Curie Doctoral Network grant.
-
22 April 2024
Charissa Roossien secures JTF subsidy to develop Health Tracker
Dr. Charissa Roossien (ENTEG) has successfully secured a Just Transition Fund (JTF) subsidy of 1.8 million euros to develop a Health Tracker for reliable respiratory and metabolic analysis.
-
16 April 2024
UG signs Barcelona Declaration on Open Research Information
In a significant stride toward advancing responsible research assessment and open science, the University of Groningen has officially signed the Barcelona Declaration on Open Research Information.