Related papers: The X-ray Transient XTE J2012+381

Detections of fast X-ray transients (FXTs) have been accrued over the last few decades. However, their origin has remained mysterious. There is now rapid progress thanks to timely discoveries and localisations with the Einstein Probe…

We report on the discovery of a new pulsating X-ray source during Rossi X-ray Timing Explorer observations of a low galactic latitude field centered at RA (J2000) = 19 hr 05 m 43 s and Dec (J2000) = +08 deg 58 arcmin 48 arcsec. Significant…

We investigate the characteristics of bright flares for a sample of supergiant fast X-ray transients and their relation to the orbital phase. We have retrieved all Swift/BAT Transient Monitor light curves, and collected all detections in…

The nature of very faint X-ray transients (VFXTs) - transient X-ray sources that peak at luminosities $L_X\lesssim10^{36} {\rm erg s^{-1}}$ - is poorly understood. The faint and often short-lived outbursts make characterising VFXTs and…

We report the detection of a dust scattering halo around a recently discovered X-ray transient, Swift J174540.7-290015, which in early February of 2016 underwent one of the brightest outbursts (F_X ~ 5e-10 erg/cm^2/s) observed from a…

We report on the Swift observations of the candidate supergiant fast X-ray transient (SFXT) IGR J16418-4532, which has an orbital period of ~3.7 d. Our monitoring, for a total of ~43 ks, spans over three orbits and represents the most…

We report results from an investigation at hard X-rays (above 18 keV) and soft X-rays (below 10 keV) of a sample of X-ray transients located on the Galactic plane and detected with the bursticity method, as reported in the latest 1,000…

We present optical and near-IR observations of QX Nor, the counterpart to the recurrent soft X-ray transient X1608-52, after its reappearance following the X-ray outburst in February 1996. The object has been seen only once before, during…

We have detected transient X-ray activity from the X-ray burster 4U~0614+091 simultaneously with BATSE/CGRO (20-100 keV) and ASM/RXTE (1-12 keV). The peak fluxes reach approximately 40 mCrab in both instruments over a period of about 20…

4U 1543-624 is a relatively bright persistent low-mass X-ray binary. Analysis of archival data from ASCA, SAX and RXTE is presented. The X-ray continuum be can modeled with the standard low-mass X-ray binary spectrum, an isothermal…

Extragalactic fast X-ray transients (FXTs) are short flashes of X-ray photons of unknown origin that last a few minutes to hours. We extend the search for extragalactic FXTs from Quirola et al. 2022 (Paper I; based on sources in the Chandra…

XTEJ1743-363 is a poorly known hard X-ray transient, that displays short and intense flares similar to those observed from Supergiant Fast X-ray Transients. The probable optical counterpart shows spectral properties similar to those of an…

Eight Accreting Millisecond X-ray Pulsars (AMXPs) are known to date. Optical and NIR observations carried out during quiescence give a unique opportunity to constrain the nature of the donor star and to investigate the origin of the…

In this work we report on observations with the Neutron Star Interior Composition Explorer of the known neutron star X-ray transient XTE J1739-285. We observed the source in 2020 February and March, finding it in a highly active bursting…

We constructed the cumulative luminosity distributions of most supergiant fast X-ray transients (SFXTs) and the classical supergiant X-ray binary (SgXB) IGR J18027-2016 by taking advantage of the long term monitoring of these sources…

The black hole X-ray transient, XTE J1118+480, has now twice been observed in outburst - 2000 and 2005 - and on both occasions remained in the low/hard X-ray spectral state. Here we present radio, infrared, optical, soft X-ray and hard…

We report on a broad-band X-ray study (0.5-60 keV) of the poorly known candidate Supergiant Fast X-ray Transient (SFXT) IGR J18462-0223, and on optical and near-infrared (NIR) followup observations of field objects. The out-of-outburst…

We report on x-ray observations of two soft x-ray transients containing neutron stars, 4U 2129+47 and EXO 0748-676. Our emphasis is on the quiescent properties of these sources. The x-ray spectrum and lightcurve of the eclipsing Low-Mass…

We had reported in Chaty, Mignani, Israel (2002) on the near-infrared (NIR) identification of a possible counterpart to the black hole candidate XTE J1908+094 obtained with the ESO/NTT. Here, we present new, follow-up, CFHT adaptive optics…

We present the results of continued monitoring of the quiescent neutron star low-mass X-ray binary XTE J1701-462 with Chandra and Swift. A new Chandra observation from 2010 October extends our tracking of the neutron star surface…