Related papers: Cyclical behaviour and disc truncation in the Be/X…

The detection of two similar periodicities (3001 and 3028 s) in the light curve of V1405 Aql, a low mass X-ray Binary (LMXRB), has attracted the attention of many observers. Two basic competing models have been offered for this system.…

The optical behaviour of the Be star in the high mass X-ray transient A0535+26/HDE245770 shows that at the periastron typically there is an enhancement in the luminosity of order 0.02 to few tenths mag, and the X-ray outburst happens about…

There is a remarkable correlation between the spin periods of the accreting neutron stars in Be/X-ray binaries (BeXBs) and their orbital periods . Recently Knigge et al. (2011) showed that the distribution of the spin periods contains two…

KS 1947+300 is a Be/X-ray binary. Despite its nearly circular orbit, it displays both giant and regular less intense X-ray outbursts. According to the viscous decretion disk model, such low eccentric binaries should not show periodic…

In this Letter we present results from INTEGRAL and RXTE observations of the spectral and timing behavior of the High Mass X-ray Binary A 0535+26 during its August/September 2005 normal (type I) outburst with an average flux…

During the 1996/1997 outburst of the X-ray transient GRO J1655-40 the Wide Field Cameras onboard BeppoSAX observed the system with nearly continuous coverage during some stages of this outburst. On two occasions we find clear evidence for…

We present the results of non linear, hydrodynamic simulations, in three dimensions, of the tidal perturbation of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc mid-plane. The…

We carried out optical high-dispersion spectroscopic monitoring of the Be disk in a Be/X-ray binary A 0535+262/V725 Tau from 2009 to 2012, covering two giant outbursts and several normal outbursts. This monitoring was performed in order to…

We examine in detail several aspects of the physics of accretion disks of possible relevance to the outburst mechanism of the black hole X-ray transients. We adopt the one dimensional, time dependent model described in detail by Cannizzo,…

Multiwavelength monitoring of Be/X-ray binaries is crucial to understand the mechanisms producing their outbursts. H 1145-619 is one of these systems, which has recently displayed X-ray activity. We investigate the correlation between the…

Circinus X-1 (Cir X-1) is a neutron star binary with an elliptical orbit of 16.6~days. The source is unique for its extreme youth, providing a key to understanding early binary evolution. However, its X-ray variability is too complex to…

Multiwavelength observations are reported here of the Be/X-ray binary pulsar system GRO J1008-57. Over ten years worth of data are gathered together to show that the periodic X-ray outbursts are dependant on both the binary motion and the…

The persistent Be/X-ray binary RX J0440.9+4431 flared in 2010 and 2011 and has been followed by various X-ray facilities Swift, RXTE, XMM-Newton, and INTEGRAL. We studied the source timing and spectral properties as a function of its X-ray…

I briefly review the theory of soft X-ray transient systems. Irradiation of the accretion disc faces by the central X-ray source determines both the occurrence and the nature of the outbursts, in particular forcing these to be long viscous…

After an X-ray binary experiences a transient jet ejection, it undergoes a phase in which its X-ray light curve is dominated, for some time, by thermal emission from an accretion disk surrounding the black hole. The accretion physics in the…

We have analyzed all archival RXTE/PCA monitoring observations of the ultraluminous X-ray source (ULX) M82 X-1 in order to study the properties of its 62 day X-ray period (Kaaret & Feng 2007). Based on its high coherence it has been argued…

The optical counterpart of the transient, millisecond X-ray pulsar SAX J1808.4-3658 was observed in four colours (BVRI) for five weeks during the 2005 June-July outburst. The optical fluxes declined by ~2 magnitudes during the first 16 days…

The mechanism of X-ray outbursts in Be X-ray binaries remains a mystery, and understanding their circumstellar disks is crucial for a solution of the mass-transfer problem. In particular, it is important to identify the Be star activities…

We report results of Swift observations for the high mass Be/X-ray binary system 1A 1118-615, during an outburst stage in January, 2009 and at a flaring stage in March, 2009. Using the epoch-folding method, we successfully detected a pulsed…

AX J0049.4-7323 is a Be/X-ray binary that shows an unusual and poorly understood optical variability that consists of periodic and bright optical outbursts, simultaneous with X-ray outbursts, characterised by a highly asymmetric profile.…