Related papers: Disc instabilities and "soft" X-ray transients
We present a numerical scheme for the evolution of an accretion disc through a dwarf nova outburst. We introduce a time-varying artificial viscosity into an existing smoothed particle hydrodynamics code optimised for two and…
Nova Mon 2012 is the third gamma-ray transient identified with a thermonuclear runaway on a white dwarf, that is, a nova event. Swift monitoring has revealed the distinct evolution of the harder and super-soft X-ray spectral components,…
In neutron star and black hole X-ray binaries the transitions between the two spectral states, hard and soft, signals the change between accretion via a hot advection-dominated flow(ADAF) and disk accretion. In a few cases the hard/soft…
In the recent years, the discovery of a new class of Galactic transients with fast and bright flaring X-ray activity, the Supergiant Fast X-ray Transients, has completely changed our view and comprehension of massive X-ray binaries. These…
We have analyzed archival Ginga data of a number of Soft X-ray Transient sources and modelled them in an attempt to constrain the geometry and physical properties of accretion. Our models include a self-consistent description of X-ray…
I present a short review of irradiation processes in close binary systems.
Accretion disks in AGN should be subject to the same type of instability as in cataclysmic variables (CVs) or in low-mass X-ray binaries (LMXBs), which leads to dwarf nova and soft X-ray transient outbursts. It has been suggested that this…
The low luminosity, X-ray flaring activity, of the sub-class of high mass X-ray binaries called Supergiant Fast X-ray Transients, has been investigated using XMM-Newton public observations, taking advantage of the products made publicly…
A method, based on the disc instability model, for testing the thermal stability of Cataclysmic Variables (CVs), is presented. It is shown that the border line between thermal stability and instability is crossed during some nova outbursts…
We present RXTE observations covering six normal outbursts of the dwarf nova SU UMa, the prototype of its class. The outbursts showed consistent X-ray behaviour with the X-ray count rate dropping suddenly by a factor of our, and with…
We present a model for the dwarf nova WZ Sge which does not require assuming unusually and unexplained low values of the viscosity alpha-parameter during exceptionally long quiescent states of this system. We propose that the inner parts of…
We review various aspects of disk instability models. We discuss problems and difficulties and present ways that have been suggested to solve them.
The current model for the outburst of stellar-mass black holes X-ray binaries is the disk instability model (DIM). An overview of this model and a discussion of its theoretical and observational challenges are given.
Recent results are presented and discussed regarding the EUV and X-ray emission of nonmagnetic cataclysmic variables. Emphasis is given to high accretion rate systems (novalike variables and dwarf novae in outburst), and to a number of…
The observations and theory of the exciting new class of galactic black hole X-ray transients is reviewed. Seven of these systems have measured mass functions or mass estimates in excess of stable neutron stars, making them excellent black…
The hard to soft state transition of the outbursts in X-ray binaries (XRBs) is triggered by the rising of the mass accretion rate due to the disk instability. In order to explain the observed correlation between the hard X-ray transition…
Supersoft X-ray sources are stellar objects which emit X-rays with temperatures of about 1 million Kelvin and luminosities well in excess of what can be produced by stellar coronae. It has generally been presumed that the objects in this…
Applications of the thermal-viscous disc instability model to various classes of cataclysmic variable very often require the accretion disc to be truncated. I argue that in most cases this inner truncation must be due to the white dwarf's…
We present spectra of accretion discs around white-dwarfs calculated with an improved and updated version of the Shaviv & Wehrse (1991) model. The new version includes line opacities and convective energy transport and can be used to…
The purpose of this study is to find transient X-ray sources in M31, and to investigate and classify their nature. Three X-ray transients were observed with Swift. For each of the three X-ray transients we use the Swift X-ray and optical…