We present the results of analyzing the XMM-Newton data obtained in 2001 November 7-8. A flare is observed simultaneously in X-ray and UV together with a quiescence. We find that during the flare event X-ray flux varies with UV with no significant time lag, indicating a close correlation of flux variation for X-ray and UV flares. An upper limit of the lag is estimated to be ∼ 1 min. From a timi...

We introduce the first phase of the Kepler -Swift Active Galaxies and Stars survey (KSwAGS), a simultaneous X-ray and UV survey of ∼6 square degrees of the Kepler field using the Swift XRT and UVOT. We detect 93 unique X-ray sources with S/N ≥3 with the XRT, of which 60 have UV counterparts. We use the Kepler Input Catalog (KIC) to obtain the optical counterparts of these sources, and construct...

We analyse five observations of the BL Lac object AO 0235+16 performed with the Chandra and XMM-Newton satellites during the years 2000–2005. In the February 2002 observation the source is found in a bright state and presents a steep X-ray spectrum, while in all the other epochs it is faint and the spectrum is hard. The soft X-ray spectrum appears to be strongly absorbed, likely by the interven...

Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections...

oxide nanoparticles can exhibit unique physical and chemical properties due to their limited size and a high density of corner or edge surface sites. in this study, mgo nanoparticle was synthesized using mg(ch3coo)2 and hexamethylenetetramine as starting materials. the structure and optical properties of these particles are investigated by using x-ray diffraction (xrd), scanning electron micros...

Abstract The spectral energy distributions (SEDs) of some blazars exhibit an ultraviolet (UV) and/or soft X-ray excess that can be modeled with different radiation mechanisms. Polarization measurements the UV/X-ray emission from may provide new and unique information about astrophysical environment blazar jets, could thus help to distinguish between scenarios. In this paper, a Monte Carlo code—...