Related papers: Investigating Supergiant Fast X-ray Transients wit…
Long Period radio Transients (LPTs) are a mysterious new class of radio transients pulsating on periods of minutes to hours. So far, eight LPTs have been discovered predominantly at low Galactic latitudes, yet their nature remains unknown.…
The nature of the minute-to-hour long Fast X-ray Transients (FXTs) localised by telescopes such as Chandra, Swift, and XMM-Newton remains mysterious, with numerous models suggested for the events. Here, we report multi-wavelength…
Aims. Fast Radio Bursts are bright radio transients whose origin has not yet explained. The search for a multi-wavelength counterpart of those events can put a tight constrain on the emission mechanism and the progenitor source. Methods. We…
We report the results from archival XMM-Newton and INTEGRAL observations of the Supergiant Fast X-ray Transient (SFXT) IGR J18483-0311 in quiescence. The 18-60 keV hard X-ray behaviour of the source is presented here for the first time, it…
We report here on the results of the analysis of Chandra, XMM-Newton and NuSTAR recent observations of the Supergiant Fast X-ray Transient XTEJ1739-302. The source was caught in a low X-ray luminosity state, from a few $10^{31}$ to…
We describe the results of the first year of a program to localize new Galactic Transient sources discovered by MAXI with NASA's Swift mission. Swift is ideally suited for follow-up of MAXI discovered transients as its X-ray Telescope (XRT)…
A fraction of high-mass X-ray binaries are supergiant fast X-ray transients. These systems have on average low X-ray luminosities, but display short flares during which their X-ray luminosity rises by a few orders of magnitude. The leading…
The Large Observatory For X-ray Timing (LOFT) is an innovative medium-class mission selected for an assessment phase in the framework of the ESA M3 Cosmic Vision call. LOFT is intended to answer fundamental questions about the behaviour of…
We report results of a novel high-energy follow-up observation of a potential Fast Radio Burst. The radio burst was detected by VLA/realfast and followed-up by the Neil Gehrels Swift Observatory in very low latency utilizing new operational…
The soft X-ray band hosts a larger, more diverse range of variable sources than any other region of the electromagnetic spectrum. They are stars, compact binaries, SMBH's, the X-ray components of Gamma-Ray Bursts, their X-ray afterglows,…
The launch of the Einstein Probe (EP) mission has revolutionized the detection and follow-up observations of fast X-ray transients (FXTs) by providing prompt and timely access to their precise localizations. In the first year of its…
Extragalactic Fast X-ray Transients (EFXTs) represent an emerging class of high-energy phenomena characterized by X-ray outbursts lasting from tens to hundreds of seconds. However, for more than half of the EFXTs, their physical origins…
Suzaku observations are presented for the high-mass X-ray binaries IGR J16207-5129 and IGR J17391-3021 (=XTE J1739-302). For IGR J16207-5129, we provide the first X-ray broadband (0.5--60 keV) spectrum from which we confirm a large…
We present a comparative study of stellar winds in classical supergiant high mass X-ray binaries (SgXBs) and supergiant fast X-ray transients (SFXTs) based on the analysis of publicly available out-of-eclipse observations performed with…
Blazars are highly variable sources over timescales that can be as low as minutes. This is the case of the High Energy Peaked BL Lac (HBL) objects showing strong variability in X-rays, which highly correlate with that of the TeV emission.…
Twenty-two extragalactic fast X-ray transients (FXTs) have now been discovered from two decades of Chandra data (analyzing ~259 Ms of data), with 17 associated with distant galaxies (>100 Mpc). Different mechanisms and progenitors have been…
The BeppoSAX Wide Field Cameras have been successful in detecting gamma-ray bursts in the 2--26 keV energy range. While most detected bursts are also strong emitters at higher energies, a significant fraction have anomalously low gamma-ray…
Recent works have discovered two fast ($\approx 10$ ks) extragalactic X-ray transients in the Chandra Deep Field-South (CDF-S XT1 and XT2). These findings suggest that a large population of similar extragalactic transients might exist in…
Temporal analysis of INTEGRAL/IBIS data has revealed a 5.7195\pm0.0007 day periodicity in the supergiant fast X-ray transient (SFXT) source AX J1845.0-0433, which we interpret as the orbital period of the system. The new-found knowledge of…
LOFT (Large Observatory For x-ray Timing) is one of the ESA M3 missions selected within the Cosmic Vision program in 2011 to carry out an assessment phase study and compete for a launch opportunity in 2022-2024. The phase-A studies of all…