Related papers: XTE J1906+090: a persistent low luminosity Be X-ra…
AX J1845.0-0433 is a transient high-mass X-ray binary discovered by ASCA. The source displays bright and short flares observed recently with INTEGRAL. The transient behaviour and the bright and short flares are studied in order to…
The International Gamma-ray Astrophysics Laboratory (INTEGRAL) has been surveying the sky above 20 keV since its launch in 2002 providing new insights into the nature of the sources that populate our Universe at soft gamma-ray energies. The…
IGR J00291+5934 is the fastest-known accretion-powered X-ray pulsar, discovered during a transient outburst in 2004. In this paper, we report on Integral and Swift observations during the 2015 outburst, which lasts for $\sim25$ d. The…
We present optical photometry and spectroscopy of the X-ray transient XTE J1859+226, obtained during outburst and its subsequent decay to quiescence. Both the X-ray and optical properties are very similar to those of well-studied black hole…
The Galactic center region was observed with the XRISM X-ray observatory during the performance verification phase in 2024 and a point-like X-ray source was detected with the X-ray imager Xtend at a position of (RA, Dec)=(17h46m10.8s,…
We present the long term X-ray light curves, detailed spectral and timing analyses of XTE J1908+094 using the Rossi X-ray Timing Explorer Proportional Counter Array observations covering two outbursts in 2002 and early 2003. At the onset of…
IGR J19140+098 was discovered during the early INTEGRAL observations of GRS1915+105 in March 2003. The following observations by INTEGRAL and RXTE show significant variability on various time scales from 100s to 1ks, but no pulsations. The…
The INTEGRAL observatory has been (re-)discovering new X-ray sources since the beginning of nominal operations in early 2003. These sources include X-ray binaries, Active Galactic Nuclei, cataclysmic variables, etc. Amongst the X-ray…
The transient X-ray source SAX J1810.8-2609 was discovered on 1998, March 10 with the Wide Field Cameras on board the BeppoSAX satellite, while observing the Galactic Bulge in the 2-28 keV energy range. On March 11, a strong type-I X-ray…
We report on new X-ray outbursts observed with Swift from three Supergiant Fast X-ray Transients (SFXTs): XTEJ1739-302, IGRJ17544-2619 and IGRJ08408-4503. The former two outbursts were caught during the monitoring campaign we have been…
A growing group of low-mass X-ray binaries are found to be accreting at very-faint X-ray luminosities of <1E36 erg/s (2-10 keV). Once such system is the new X-ray transient IGR J17494-3030. We present Swift and XMM-Newton observations…
In the beginning of 2023 the Be transient X-ray pulsar RX J0440.9+4431 underwent a fist-ever giant outburst observed from the source peaking in the beginning of February and reaching peak luminosity of $\sim 4.3\times10^{37}$ erg s$^{-1}$.…
We report the discovery of a high-energy transient with the IBIS/ISGRI detector on board the INTEGRAL observatory. The source, namely IGR J00291+5934, was first detected on 2nd December 2004 in the routine monitoring of the IBIS/ISGRI…
We have discovered an x-ray source, SAX J0635+0533, with a hard spectrum within the error box of the GeV gamma-ray source in Monoceros, 2EG J0635+0521. The unabsorbed x-ray flux is 1.2*10^-11 erg cm^-2 s^-1 in the 2-10 keV band. The x-ray…
We present recent observations of the X-ray pulsar SAX J1324-6200 obtained in December 2007 with the Swift satellite yielding a significant improvement in the source localization with respect to previous data and a new measurement of the…
We present the high-resolution spectrum of the accretion-powered millisecond pulsar XTE J0929-314 during its 2002 outburst, measured using the Low Energy Transmission Grating Spectrometer onboard the Chandra X-ray Observatory. The 1.5-25.3…
XTE J1829-098 is a transient X-ray pulsar with a period of ~7.8 s. It is a candidate Be star system, although the evidence for this is not yet definitive. We investigated the twenty-year long X-ray light curve using the Rossi X-ray Timing…
After nearly a decade in quiescence, the accreting millisecond pulsar IGR J17511$-$3057 displayed a new outburst on 2025 February 11, its third since discovery, following previous activity in 2009 and 2015. We report on an XMM-Newton Target…
In 2005 March 22nd, the INTEGRAL satellite caught a type-I X-ray burst from the unidentified source XMMU J174716.1-281048, serendipitously discovered with XMM-Newton in 2003. Based on the type-I X-ray burst properties, we derived the…
We studied the soft-X-ray emission of five hard-X sources: IGR J08262-3736, IGR J17354-3255, IGR J16328-4726, SAX J1818.6-1703 and IGR J17348-2045. These sources are: a confirmed supergiant high mass X-ray binary (IGR J08262-3736);…