Related papers: Classifying IGR J18007-4146 as an intermediate pol…

KPD 0005+5106, with an effective temperature of $\simeq$200,000 K, is one of the hottest white dwarfs (WDs). ROSAT unexpectedly detected "hard" ($\sim$1 keV) X-rays from this apparently single WD. We have obtained Chandra observations that…

The spectra of several X-ray binary pulsars display a clear soft excess, which in most cases can be described with a blackbody model, above the main power-law component. While in the high-luminosity sources it is usually characterized by…

J191213.72-441045.1 is a binary system composed of a white dwarf and an M-dwarf in a 4.03-hour orbit. It shows emission in radio, optical, and X-ray, all modulated at the white dwarf spin period of 5.3 min, as well as various orbital…

We present the transient nature of INTEGRAL source IGR J17285-2922, identified from a single period of activity during an IBIS/ISGRI Galactic Centre Deep Exposure in September 2003. The source has a maximum detection significance of 14…

Results of analysis of RXTE observations of strongly absorbed X-ray sources IGR J16318-4848 and IGR J16358-4726 are presented. Careful subtraction of Galactic ridge emission contribution to the observed spectra of RXTE/PCA allowed us to…

We report on the first pointed X-ray observations with XMM-Newton and RXTE satellites of the X-ray source RXJ0757.0+6306=HT Cam. We detect a strong 515s X-ray modulation confirming the optical photometric period found in 1998, which…

We present spectral and energy dependent timing characteristics of the hard X-ray transient IGR J17497-2821 based on XMM-Newton observations performed five and nine days after its outburst on 2006 September 17. We find that the source…

IGR~J19149+1036 is a high mass X-ray binary detected by INTEGRAL in 2011 in the hard X-ray domain. We have analyzed the BAT survey data of the first 103 months of the Swift mission detecting this source at a significance level of ~30…

We report the discovery of a new cataclysmic variable (CV) among unidentified objects from the ASCA Galactic Plane Survey made using the Virtual Observatory data mining. First, we identified AX J194939+2631 with IPHAS J194938.39+263149.2,…

We present a reanalysis of XMM-Newton Reflection Grating Spectrometer data of the classical nova V2491 Cyg obtained from two different pointings, 40 d and 50 d after outburst utilizing the SRON software SPEX version 2.05.04. We aim to model…

This work presents an investigation of the stochastic X-ray variability from the 164 Hz accreting millisecond pulsar IGR J17062-6143, based on regular observations collected with the Neutron Star Interior Composition Explorer between 2017…

IGR J16195-4945 is a hard X-ray source discovered by INTEGRAL during the Core Program observations performed in 2003. We analyzed the X-ray emission of this source exploiting the Swift-BAT survey data from December 2004 to March 2015, and…

IGR J18179-1621 is a hard X-ray binary transient discovered recently by INTEGRAL. Here we report on detailed timing and spectral analysis on IGR J18179-1621 in X-rays based on available INTEGRAL and Swift data. From the INTEGRAL analysis,…

The microquasar 1E1740.7-2942, also known as the "Great Annihilator", was observed by NuSTAR in the Summer of 2012. We have analyzed in detail two observations taken ~2 weeks apart, for which we measure hard and smooth spectra typical of…

We report the results of photometry of the intermediate polar V647 Aur. Observations were obtained over 42 nights in 2012 and 2013. The total duration of the observations was 246 h. We clearly detected three oscillations with periods of…

Context. Observations of cataclysmic variables in globular clusters appear to show a dearth of outbursts compared to those observed in the field. A number of explanations have been proposed, including low mass-transfer rates and/or moderate…

We report the association of the INTEGRAL source IGR J18027-2016 with the BeppoSAX source SAX J1802.7-2017. IGR J18027-2016 is seen to be a weak, persistent source by the IBIS/ISGRI instrument on board INTEGRAL with an average source count…

In cataclysmic variables (CVs), accretion onto white dwarfs produces high temperature, high density plasmas. They cool down from kT~10 keV via bremsstrahlung continuum and K and L shell line emissions. The small volume around white dwarfs…

The nearby galaxy NGC 300 is hosting two luminous transient supersoft X-ray sources with bolometric luminosities above 3x10^38 erg/s, assuming simple black-body spectra with temperatures around 60-70 eV. For one of these, SSS1, a periodic…

For the He/N nova M31N 2007-12b, we analyzed XMM-Newton EPIC and Chandra HRC-I observations of our monitoring program performed at intervals of ten days and added results of a XMM-Newton target of opportunity observation and Swift XRT…