Related papers: The extraordinary X-ray spectrum of XTE J0421+560
We present an INTEGRAL data analysis of the X-ray transient \object{SAX J2103.5+4545} during two outbursts detected in December 2002. The INTEGRAL coordinates and error circle agree with the position of the recently proposed optical…
ROTSE-IIId observations of the Be/X-ray transient system KS 1947+300 obtained between September 2004 and December 2005 make it possible to study the correlation between optical and X-ray activity. The optical outburst of 0.1 mag was…
We report on spectral and timing analysis of BeppoSAX data of the 13.6 s period transient X-ray pulsar EXO 0531-6609.2. Observations were carried out in March 1997 and October 1998, catching the source during a high and a low emission…
This work is devoted to the study of the broadband 0.8-79 keV spectral and timing properties of the poorly studied X-ray pulsar XTE J1859+083 during its 2015 outburst based on the data from the NuSTAR and Swift observatories. We show that…
We present the results of a ROSAT Position Sensitive Proportional Counter observation of the variable radio star \ls. The source has a power law spectrum with photon index 1.1 +/- 0.3 and a luminosity of 5.9 x 10^{33} erg/s in the 0.1 -2.4…
A long ($>100,000$ seconds) observation of the bright BL Lac object PKS 2155-304 has been carried out with the Narrow Field Instruments of the BeppoSAX satellite as part of the Science Verification Phase. The source was detected between 0.1…
We present an analysis of all SAX observations of NGC 4151. This source was observed 5 times from 1996 to 2001 with durations ranging from a day to four days. The intrinsic continuum, is absorbed at low energies by a complex system: a cold…
We report on two XMM-Newton observations of the low-mass X-ray binary X 1254-690. During an XMM-Newton observation of the low-mass X-ray binary in 2001 January a deep X-ray dip was seen while in a second observation one year later no dips…
FUSE spectra were obtained of the supersoft X-ray binary RX J0019.8+2156 (QR And) during 16 consecutive spacecraft orbits, covering the binary orbit (P=15.85 hr) with about 0.2 phase overlap. The spectrum is dominated by strong H2…
We present results of a decade of X-ray observations of the gamma-ray loud binary HESS J0632+057, and interpret the available broadband data in view of the system geometry and emission mechanisms. We have performed an analysis of all X-ray…
We have studied the rapid X-ray variability of three extragalactic TeV gamma-ray sources; Mrk 421, Mrk 501 and PKS 2155-304. Analyzing the X-ray light curves obtained from ASCA and/or RXTE observations between 1993 and 1998, we have…
A new x-ray transient, designated XTE J1739-302, was discovered with the Proportional Counter Array (PCA) on the Rossi X-ray Timing Explorer (RXTE) in data from 12 August 1997. Although it was the brightest source in the Galactic Center…
XTE J1810-189 underwent an outburst in 2008, and was observed over $\sim 100$ d by RXTE. Performing a time-resolved spectral analysis on the photospheric radius expansion burst detected on 2008 May 4, we obtain the source distance in the…
We present radio observations of the black hole X-ray transient XTE J1720-318, which was discovered in 2003 January as it entered an outburst. We analyse the radio data in the context of the X-ray outburst and the broad-band spectrum. An…
We report on the spectral analysis of the peculiar source Cir X-1 observed by the BeppoSAX satellite when the X-ray source was near the periastron. A flare lasting $\sim 6 \times 10^3$ s is present at the beginning of the observation. The…
The BL Lac object Mkn~421 was observed three times by the X-ray observatory BeppoSAX in consecutive days during 1997 April and May. The source was in a quiescent state, with an average 2-10 keV flux of 9.0 x 10^(-11) erg/cm/cm/s. Flux…
The XMM-Newton spectrum of the black hole candidate XTE J1652-453 shows a broad and strong Fe K-alpha emission line, generally believed to originate from reflection of the inner accretion disc. These data have been analysed by Hiemstra et…
Aims. We present a multiwavelength study of the Be/X-ray binary system SAX J2103.5+4545 with the goal of better characterizing the transient behaviour of this source. Methods. SAX J2103.5+4545 was observed by Swift-XRT four times in 2007…
We report on Chandra X-ray Observatory (CXO) High-Energy Transmission Grating (HETG) spectra of the dipping Low Mass X-ray Binary (LMXB) 1A 1744-361 during its July 2008 outburst. We find that its persistent emission is well modeled by a…
We report multifrequency radio observations of XTE J1550-564 obtained with the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array at the time of its discovery and subsequent hard and soft X-ray outburst in…