Related papers: X-ray transients in quiescence
Accretion driven millisecond X-ray pulsars can accrete over a wide range of mass flow rates. The pulsations persist even at small accretion rates at which these objects would be expected to be in the propeller stage. We argue that the inner…
Burst-only sources are X-ray sources showing up only during short bursts but with no persistent emission (at least with the monitoring instrument which led to their discovery). These bursts have spectral characteristics consistent with…
We present the timing and spectral properties of the transient Be/X-ray binary pulsar 3A 0535+262 during quiescence using three observations with the narrow field imaging instruments (NFI) of BeppoSAX. Assuming a distance of 2 kpc for this…
During observation campaigns of the Galactic Bulge region, BeppoSAX detected a total of 21 new X-ray bursters in about 6 years of operation. These sources are mostly transient and often feature a hard X-ray spectrum, extending up to ~ 200…
We study the formation of low-mass X-ray binaries with a black hole as accreting object. The performed semi-analytic analysis reveals that the formation rate of black holes in low-mass X-ray binaries is about two orders of magnitude smaller…
X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or…
Supergiant Fast X-ray transients are a subclass of high mass X-ray binaries displaying a peculiar and still poorly understood extreme variability in the X-ray domain. These sources undergo short sporadic outbursts (LX ~ 10^36 - 10^37…
The Rossi X-Ray Timing Explorer (RXTE) has found that the neutron stars in low-mass X-ray binaries exhibit oscillations in the range 300-1200 Hz. Persistent emission may exhibit one or both of two features. In bursts a nearly coherent…
It is thought that neutron stars in low-mass binary systems can accrete matter and angular momentum from the companion star and be spun-up to millisecond rotational periods. During the accretion stage, the system is called a low-mass X-ray…
Using the Modules for Experiments in Stellar Astrophysics code, we investigate the influences of irradiation on ultra-compact X-ray binary (UCXB) evolution. Although the persistent UCXBs have short orbital periods which result in high…
We investigate the dependence of observational properties of black hole X-ray binaries on the inclination angle i of their orbits. We find the following: (1) Transient black hole binaries show no trend in their quiescent X-ray luminosities…
A brief overview is given of the observations of accretion disks in X-ray binaries, discussing their geometry, their effect on the rotation period of the accreting object, their optical and X-ray spectra, time variability, and radio…
A neutron star low-mass X-ray binary is a binary stellar system with a neutron star and a low-mass companion star rotating around each other. In this system the neutron star accretes mass from the companion, and as this matter falls into…
We present results of our analysis of a set of RXTE/PCA observations of X-ray flares/bursts with burst cycle ranging from 30 to 1300 s from the Galactic X-ray transient source GRS 1915+105 during last four years. These flares/bursts can be…
Recent X-ray observations have detected a class of very faint X-ray transients in the Galaxy which probably reveal a previously unrecognised type of accretion on to neutron stars or black holes. We show that these systems cannot have…
Supergiant Fast X-ray Transients (SFXTs) are a new class of HMXBs discovered thanks to the monitoring of the Galactic plane performed with the INTEGRAL satellite in the last 5 years. These sources display short outbursts (significantly…
Supergiant Fast X-ray Transients (SFXTs) are a sub-class of High Mass X-ray Binaries (HMXBs) associated with OB supergiant companions and displaying transient X-ray activity. This behaviour is quite surprising since HMXBs hosting…
We summarise all the reported detections of, and upper limits to, the radio emission from persistent (i.e. non-transient) X-ray binaries. A striking result is a common mean observed radio luminosity from the black hole candidates (BHCs) in…
Many low-mass X-ray binaries show both hard and soft spectral states. For several sources the transitions between these states have been observed, mostly from the soft to the hard state during a luminosity decrease. In a few cases also the…
Millisecond radio pulsars are neutron stars that have been spun-up by the transfer of angular momentum during the low-mass X-ray binary phase. The transition from an accretion-powered to a rotation-powered pulsar takes place on evolutionary…