Related papers: Three X-ray transients in M31 observed with Swift
Swift J1357.2$-$0933 is a black-hole candidate X-ray transient, which underwent its third outburst in 2019, during which several multi-wavelength observations were carried out.~Here, we report results from the \emph{Neil Gehrels Swift} and…
[Abridged] Classical novae (CNe) represent the major class of supersoft X-ray sources (SSSs) in the central region of our neighbouring galaxy M 31. We performed a dedicated monitoring of the M 31 central region with XMM-Newton and Chandra…
Monitor of All sky X-ray Image (MAXI) discovered a new outburst of an X-ray transient source named MAXI J1421-613. Because of the detection of three X-ray bursts from the source, it was identified as a neutron star low-mass X-ray binary.…
We report the results of Chandra and XMM-Newton observations of a new outburst of an ultra-luminous X-ray source in M101. During a Chandra monitoring observation of M101, M101 ULX-1 was found to be in outburst in 2004 December, the second…
The X-ray transient eclipsing source MXB 1659-298 went into outburst in 1999 and 2015. During these two outbursts the source was observed by XMM-Newton, nuSTAR, and Swift/XRT. Using these observations, we studied the broadband spectrum of…
We discovered eclipses and dips in two luminous (and highly variable) X-ray sources in M\,51. One (CXOM51 J132943.3$+$471135) is an ultraluminous supersoft source, with a thermal spectrum at a temperature of about 0.1 keV and characteristic…
The Second Swift-XRT Point Source catalogue offers a combination of sky coverage and sensitivity and presents an invaluable opportunity for transient discovery. We search the catalogue at the positions of inactive and active galaxies, and…
V745 Sco is a recurrent nova, with the most recent eruption occurring in February 2014. V745 Sco was first observed by Swift a mere 3.7 hr after the announcement of the optical discovery, with the super-soft X-ray emission being detected…
We report here on the most recent results obtained on a new class of High Mass X-ray Binaries, the Supergiant Fast X-ray Transients. Since October 2007, we have been performing a monitoring campaign with Swift of four SFXTs (IGRJ17544-2916,…
The X-ray source 3XMM~J150052.0+015452 was discovered as a spectacular tidal disruption event candidate during a prolonged ($>11$ yrs) outburst (Lin et al. 2017). It exhibited unique quasi-soft X-ray spectra of characteristic temperature…
MAXI J1807+132 is an X-ray transient discovered during the decay of an outburst in 2017. We present optical and X-ray monitoring of the source over more than 125 days, from outburst to quiescence. The outburst decay is characterized by the…
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 report on a long-term monitoring of a newly discovered X-ray nova, MAXI J1910-057 (= Swift J1910.2-0546), by MAXI and Swift. The new X-ray transient was first detected on 2012 May 31 by MAXI Gas Slit Camera (GSC) and Swift Burst Alert…
The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a…
The X-ray transient eclipsing source MXB 1659-298 went in outburst in 1999 and 2015, respectively, during which it was observed by XMM-Newton, NuSTAR and Swift. Using these observations we studied the broadband spectrum of the source to…
We present the results of a joint Swift-NuSTAR spectroscopy campaign on M31. We focus on the five brightest globular cluster X-ray sources in our fields. Two of these had previously been argued to be black hole candidates on the basis of…
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 present the results from INTEGRAL and Swift/XRT observations of the hitherto poorly studied unidentified X-ray transient AX J1949.8+2534, and on archival multiwavelength observations of field objects. Bright hard X-ray outbursts have…
We have performed a statistical study of the properties of 110 bright X-ray outbursts in 36 low-mass X-ray binary transients (LMXBTs) seen with the All-Sky Monitor (2--12 keV) on board the {\it Rossi X-ray Timing Explorer} ({\it RXTE}) in…
Context. Supergiant fast X-ray transients are a subclass of high mass X-ray binaries that host a neutron star accreting mass from the wind of its OB supergiant companion. They are characterized by an extremely pronounced and rapid…