Related papers: XTE J1901+014 - the First Low-Mass Fast X-ray Tran…
Recent XMM-Newton and Chandra observations of the high mass X-ray binary LS 5039 / RX J1826.2-1450 caught the source in a faint X-ray state. In contrast with previous RXTE observations, we fail to detect any evidence of iron line emission.…
We report results of the INTEGRAL Target of Opportunity observations of the transient X-ray burster XTE J1810-189. The observations were performed on April 3--6, 2008, soon after the discovery of the source and near the peak of its…
MAXI J1834-021 is a new X-ray transient that was discovered in February 2023. We analysed the spectral and timing properties of MAXI J1834-021 using NICER, NuStar and Swift data collected between March and October 2023. The light curve…
We report the first detection of radio emission from any anomalous X-ray pulsar (AXP). Data from the Very Large Array (VLA) MAGPIS survey with angular resolution 6" reveals a point-source of flux density 4.5 +/- 0.5 mJy at 1.4 GHz at the…
We report the discovery of a fairly bright transient during observations with the Wide Field Cameras on board the BeppoSAX satellite in September 1996. It was detected at a peak intensity of 0.1 Crab (2 to 10 keV) and lasted between 6 and…
We report on multi-band observations of the transient source Swift J0840.7-3516, which was detected in outburst in 2020 February by the Neil Gehrels Swift Observatory. The outburst episode lasted just ~5 days, during which the X-ray…
We present multiwavelength observations of the newly discovered X-ray transient XTE J1118+480 obtained in the rising phase of the 2000 April outburst. This source is located at unusually high Galactic latitude and in a very low absorption…
Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact…
Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and…
We present a detailed NIR/optical/UV study of the transient low mass X-ray binary 1RXS J180408.9-342058 performed during its 2015 outburst, aimed at determining the nature of its companion star. We obtained three optical spectra at the 2.1…
In 1996 during Rossi X-ray Timing Explorer (RXTE) observations of SGR 1900+14, the 89-s X-ray pulsar XTE J1906+09 was discovered. As a result of monitoring campaigns of SGR 1900+14, XTE J1906+09 was also monitored regularly in 1996…
In 2003 a previously unpulsed Einstein and ROSAT source cataloged as soft and dim (Lx of few 10^33 ergs) thermal emitting object, namely XTE J1810-197, was identified as the first unambiguous transient Anomalous X-ray Pulsar. Two years…
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 report on the discovery of an ultrasoft X-ray transient source, 3XMM J152130.7+074916. It was serendipitously detected in an XMM-Newton observation on 2000 August 23, and its location is consistent with the center of the galaxy SDSS…
We have discovered four X-ray bursts, recorded with the Rossi X-ray Timing Explorer Proportional Counter Array between 2003 September and 2004 April, that we show to originate from the transient magnetar candidate XTE J1810-197. The burst…
An outburst of the X-ray transient source XTE J1806--246 (2S1803--245) has been observed by Rossi X-ray Timing Explorer in April-July 1998. Strong quasi-periodical oscillations (QPO) with a central peak frequency around 9 Hz was detected in…
We present the latest results from a multi-epoch timing and spectral study of the Transient Anomalous X-ray Pulsar XTE J1810-197. We have acquired seven observations of this pulsar with the Newton X-ray Multi-mirror Mission (XMM-Newton)…
We report the results from an archival XMM-Newton observation of the Supergiant Fast X-ray Transient (SFXT) IGR J18483-0311 during its apastron passage. The measured 0.5--10 keV luminosity state (1.3$\times10^{33}$ erg s$^{-1}$) is the…
Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >1e14 G, according to the 'magnetar' model. The radio…
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…