Related papers: HST Observations of X-Ray Transients

We have studied the hard X-ray variability of the soft X-ray transient GRO J0422+32 with BATSE in the 20-100 keV energy band. Our analysis covers 180 days following the first X-ray detection of the source on 1992 August 5, fully covering…

The black hole X-ray binary V4641 Sgr experienced an outburst in 2002 May which was detected at X-ray, optical, and radio wavelengths. The outburst lasted for only 6 days, but the object remained active for the next several months. Here we…

We report the detection of type C QPO along with the upper harmonic in the commensurate ratio of 1:2 in the two observations of the low-mass black hole transient H~1743--322 jointly observed by \textit{XMM-Newton} and \textit{NuSTAR} during…

IGR J17464-3213, already known as the HEAO-1 transient source H1743-322, has been detected during a state transition by the SPI/INTEGRAL telescope. We describe the spectral evolution and flaring activity of IGR J17464-3213/H1743-322 from…

We have examined fifteen days of CGRO/BATSE data, obtained during the first outburst of the black-hole candidate source GRO J1655-40, to search for rapid variability of its X-ray flux. We find no evidence for significant variability of GRO…

We report the discovery of emission features in the X-ray spectrum of GRO J1655-40 obtained with RXTE during the observation of 1997, Feb 26. We have fitted the features firstly by two Gaussian lines which in four spectra analysed have…

The black hole X-ray transient, XTE J1118+480, has now twice been observed in outburst - 2000 and 2005 - and on both occasions remained in the low/hard X-ray spectral state. Here we present radio, infrared, optical, soft X-ray and hard…

We present the optical to near-infrared spectrum of MAXI J1659-152, during the onset of its 2010 X-ray outburst. The spectrum was obtained with X-shooter on the ESO - Very Large Telescope (VLT) early in the outburst simultaneous with high…

We present the results of hydrodynamical simulations of the disk photosphere irradiated by strong X-rays produced in the inner most part of the disk. As expected, the irradiation heats the photosphere and drives a thermal wind. To apply our…

We report the discovery and multi-wavelength characterization of the Galactic transient EP J174942.2$-$384834, first detected by the Einstein Probe during a faint X-ray outburst in March 2025. Coordinated follow-up observations revealed two…

In this paper we report on a long multi-wavelength observational campaign of the supergiant fast X-ray transient prototype IGR J17544-2619. A 150 ks-long observation was carried out simultaneously with XMM-Newton and NuSTAR, catching the…

We report on the long-term flux relaxation of the magnetar SGR 1627-41 after its 2008 outburst, and evidence for hard X-ray excess measured with NuSTAR. We use new observations made with Chandra and XMM-Newton, and an archival NuSTAR…

IGR J11215-5952 is a hard X-ray transient discovered in 2005 April by INTEGRAL and a member of the new class of HMXB, the Supergiant Fast X-ray Transients (SFXTs). While INTEGRAL and RXTE observations have shown that the outbursts occur…

We report new X-ray results from the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), Swift, Chandra, and XMM-Newton observations of the hitherto poorly studied unidentified X-ray transient IGR J17419-2802. We studied in detail…

We present results for the first observed outburst from the transient X-ray binary source MAXI J0637-430. This study is based on eight observations from the Nuclear Spectroscopic Telescope Array (NuSTAR) and six observations from the Neil…

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 on the results of a series of X-ray observations of the transient black hole candidate XTE J2012+381 during the 1998 outburst performed with the BeppoSAX satellite. The observed broad-band energy spectrum can be described with the…

We report on timing and spectral observations of the 2000 outburst of XTE J1550-564 made by the Unconventional Stellar Aspect (USA) Experiment on board the Advanced Research and Global Observation Satellite (ARGOS). We observe a…

The Spitzer GLIMPSE survey has revealed a number of "Extended Green Objects" (EGOs) which display extended emission at 4.5 micron. These EGOs are potential candidates for high mass protostellar outflows. We have used high resolution (< 1")…

Outbursts of young stellar objects occur when the mass accretion rate suddenly increases. However, such outbursts are difficult to detect for deeply embedded protostars due to their thick envelope and the rarity of outbursts. The near-IR…