Related papers: RX J1420.4+5334 - another tidal disruption event?
We present ROSAT HRI observations of six quasars with redshifts >3.4: PKS 0335-122, S4 0620+389, B1422+231, PKS 2215+02, Q 2239-386 and PC 2331+0216. We include the observation of the radio-quiet quasar BG 57 9, whose redshift has recently…
We report the observation of a possible optical counterpart to the recently discovered X-ray source NuSTAR J053449+2126.0 (J0534 in short). We observed the source location using the 1.5-m Telescope (RTT150) to search for an optical…
We report the discovery of the first transient with MeerKAT, MKT J170456.2$-$482100, discovered in ThunderKAT images of the low mass X-ray binary GX339$-$4. MKT J170456.2$-$482100 is variable in the radio, reaching a maximum flux density of…
The Bursting Pulsar, GRO J1744-28, has been observed with the Rossi X-ray Timing Explorer (RXTE) regularly since the launch of the satellite in December 1995. This accretion driven pulsar has undergone two outbursts which have been…
We report the results of eROSITA and NICER observations of the June 2020 outburst of the Be/X-ray binary pulsar RX J0529.8-6556 in the Large Magellanic Cloud, along with the analysis of archival X-ray and optical data from this source. We…
RX J0209.6-7427 is an X-ray source in the Magellanic Bridge that was first detected in 1993, but not seen again till 2019. It has been identified as a member of the Be/X-ray binary class, a category of objects that are well established as…
SAX J0635.2+0533 is a binary pulsar with a very short pulsation period ($P$ = 33.8 ms) and a high long-term spin down ($\dot P$ $>$ 3.8$\times10^{-13}$ s s$^{-1}$), which suggests a rotation-powered (instead of an accretion-powered) nature…
Swift J164449+573451 is a peculiar outburst which is most likely powered by the tidal disruption of a star by a massive black hole. Within the tidal disruption scenario, we show that the periastron distance is considerably smaller than the…
X-ray emission from the gravitational wave transient GW170817 is well described as non-thermal afterglow radiation produced by a structured relativistic jet viewed off-axis. We show that the X-ray counterpart continues to be detected at 3.3…
We present X-ray, UV, optical, and radio observations of the nearby ($\approx78$ Mpc) tidal disruption event (TDE) AT2021ehb/ZTF21aanxhjv during its first 430 days of evolution. AT2021ehb occurs in the nucleus of a galaxy hosting a $\approx…
We report the first time-resolved photometric and spectroscopic optical observations of the X-ray source RX J2133.7+5107, identified in the ROSAT survey. A clear persistent optical light pulsation is discovered with fast photometry at a…
The recently discovered high-energy transient Swift J164449.3+573451 (Sw J1644+57) is thought to arise from the tidal disruption of a passing star by a dormant massive black hole. Modeling of the broadband emission suggests the presence of…
Recent analysis suggests that the faint optical point source observed around Fomalhaut from 2004-2014 (Fomalhaut b) is gradually fading and expanding, supporting the case that it may be a dispersing dust cloud resulting from the sudden…
We have discovered an obscured active galaxy at redshift z = 1.246 identified with the ROSAT X-ray source RX J1011.2+5545. We report on multiwavelength observations of this source and discuss its X-ray, optical and radio properties. This is…
Supergiant fast X-ray transients are a new class of high mass X-ray binaries recently discovered with INTEGRAL. Hours long outbursts from these sources have been observed on numerous occasions at luminosities of ~1E36-1E37 erg/s, whereas…
We report the serendipitous discovery of a bright point source flare in the Abell cluster 1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 keV flux declined…
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…
We report on the first long (~32 ks) pointed XMM-Newton observation of the supergiant fast X-ray transient IGRJ16479-4514. Results from the timing, spectral and spatial analysis of this observation show that the X-ray source IGRJ16479-4514…
We report X-ray observations of the newly discovered pulsating white dwarf eRASSU J191213.9-441044 with Spectrum Roentgen Gamma and eROSITA (SRG/eROSITA) and XMM-Newton. The new source was discovered during the first eROSITA all-sky survey…
The X-ray source RX J0002+6246 was discovered close to the supernova remnant CTB1 in a ROSAT observation performed in 1992. The source phenomenology (soft spectrum, apparent lack of counterparts, possible pulsations at 242 ms, hints for…