Related papers: Complex X-ray spectral variability in Mkn 421 obse…
We report results from the observations of the well studied TeV blazar Mrk 421 with the Swift and the Suzaku satellites in December 2008. During the observation, Mrk 421 was found in a relatively low activity state, with the corresponding…
We use XMM-Newton and Swift data to study spectral variability in the ultraluminous X-ray source (ULX), Holmberg IX X-1. The source luminosity varies by a factor 3-4, giving rise to corresponding spectral changes which are significant, but…
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…
RX J1140.1+0307 (hereafter RX1140) is a Narrow Line Seyfert 1 (NLS1) with one of the lowest black hole masses known in an AGN (M ${\le} 10^6$ M$_{\odot}$). We show results from two new {\it XMM-Newton} observations, showing soft 2-10~keV…
We study the multi-band variability and correlations of the TeV blazar Mrk 421 on year time scales, which can bring additional insight on the processes responsible for its broadband emission. We observed Mrk 421 in the very high energy…
An XMM-Newton observation of the luminous Seyfert 1 galaxy 1H 0419-577 in September 2002, when the source was in an extreme low-flux state, found a very hard X-ray spectrum at 1-10 keV with a strong soft excess below ~1 keV. Comparison with…
We present results based on an XMM-Newton observation of the high luminosity narrow-line QSO PHL 1092 performed in 2003 January. The 0.3 - 10 keV spectrum is well described by a model which includes a power-law (Gamma ~ 2.1) and two…
4U 0614+09 is a low-mass X-ray binary with a weakly magnetized neutron star primary. It shows variability on time scales that range from years down to ~0.8 milliseconds. Before the Chandra and XMM-Newton era, emission features around 0.7…
We report results from our monitoring of the BL Lac object Mrk 421 in the near-IR $J$ band. The observations, aimed at studying the intraday variability (IDV) of the object, were carried out systematically over an extended (and…
We present the results of an extensive analysis of the optical, ultraviolet, X-ray and $\gamma$-ray data collected from the observations of the BL Lac objects prototype BL Lacertae carried out over a period of nearly 13 years, between…
We report results obtained from a systematic analysis of X-ray lags in a sample of black hole X-ray binaries, with the aim of assessing the presence of reverberation lags and studying their evolution during outburst. We used XMM-Newton and…
We present an analysis of the XMM-Newton observations of the symbiotic recurrent nova T CrB, obtained during its active phase that started in 2015. The XMM-Newton spectra of T CrB have two prominent components: a soft one (0.2 - 0.6 keV),…
We present the results of X-ray observations of the well-studied TeV blazar Mrk 421 with the Suzaku satellite in 2006 April 28. During the observation, Mrk 421 was undergoing a large flare and the X-ray flux was variable, decreasing by ~ 50…
(Abridged) We present here a long (100ks) XMM-Newton follow-up of the Seyfert 1.8 galaxy ESO113-G010 performed in November 2005, in order to study over a longer time-scale its main X-ray properties. The source was found in a higher/softer…
BL Lacertae is a blazar known for its high flux variability and occasional broadband flares of unknown origin. It was in an extended flaring state from July 2020 until the end of 2021, making it an ideal candidate to study spectral and…
We report the results from a recent 133 ks XMM-Newton observation of a highly super-Eddington narrow-line Type-1 QSO RX J0439.6-5311. This source has one of the steepest AGN hard X-ray slopes, in addition to a prominent and smooth soft…
We report on the XMM-Newton observation of the HMXRB X Persei, the prototype of the persistent and low-luminosity Be/neutron star pulsars, which was performed on February 2003. The source was detected at a luminosity level of ~ 1.4x10^35…
It is surprising to find a fact for migration in the peak positions of synchrotron spectra energy distribution component during in the activity epochs of Mrk 421, accompanying with an orphan flaring at the X-ray and GeV-TeV $\gamma$-ray…
We report on an X-ray observation of the Be X-ray Binary Pulsar RX J0059.2-7138, performed by XMM-Newton in March 2014. The 19 ks long observation was carried out about three months after the discovery of the latest outburst from this Small…
We report on the XMM-Newton observation of the Be/neutron star X-ray binary system RX J0146.9+6121, a long period (~ 23 m) pulsar in the NGC 663 open cluster. The X-ray luminosity decreased by a factor two compared to the last observation…