Related papers: Hard X-ray Emission Associated with White Dwarfs I…
We present Suzaku observations of five hard X-ray selected nearby Seyfert 2 galaxies. All the sources were clearly detected with the pin Hard X-ray Detector up to several tens of keV, allowing for a fairly good characterization of the…
We introduce the first results from an ongoing, systematic survey for new symbiotic stars selected from the AAO/UKST SuperCOSMOS H$\alpha$ Survey (SHS). The survey aims to identify and characterise the fainter population of symbiotic stars…
Results from a concerted Hubble Space Telescope (HST) survey of nearby white dwarfs for substellar objects is presented. A total of 7 DAZ white dwarfs with distances of $<$ 50 pc had high contrast and high spatial resolution NICMOS…
We report the discovery of three X-ray sources within the radio shell G318.2+0.1, one of which may be extended. Two of the sources were detected during the \sax Galactic Plane Survey and one was found in archival \ros data. The fainter \sax…
ROSAT observations found no convincing evidence for X-ray sources located in local dwarf spheroidal galaxies (dSph). Now with more sensitive instruments on board Chandra and XMM-Newton we can reach fainter luminosity levels. We report on an…
Optical spectroscopic observations of white dwarf stars selected from catalogs based on the Gaia DR2 database reveal nine new gaseous debris disks that orbit single white dwarf stars, about a factor of two increase over the previously known…
Interacting binaries in which a white dwarf accretes material from a companion - cataclysmic variables (CVs) in which the mass donor is a Roche-lobe filling star on or near the main sequence, and symbiotic stars in which the mass donor is a…
We report the discovery of weak yet hard X-ray emission from the Wolf-Rayet (WR) star WR142 with the XMM-Newton X-ray telescope. Being of spectral subtype WO2, WR142 is a massive star in a very advanced evolutionary stage, short before its…
Context. A short duration burst reminiscent of a soft gamma-ray repeater/anomalous X-ray pulsar behaviour was detected in the direction of LS I +61 303 by the Swift satellite. While the association with this well known gamma-ray binary is…
Recent hard X-ray surveys have proven to be effective in discovering large numbers of X-ray sources that, despite the likely association with active nuclei, appear to be characterized by "peculiar" properties. Among these "exotic" source…
We report the detection of X-ray emission from the jet-driving symbiotic star MWC 560. We observed MWC 560 with XMM-Newton for 36 ks. We fitted the spectra from the EPIC pn, MOS1 and MOS2 instruments with XSPEC and examined the light curves…
We report on the spectroscopic confirmation of 68 new bright ($G=13.5-17.2$ mag) and blue (pre-)white dwarfs (WDs). This finding has allowed us to almost double the number of the hottest ($T_{\mathrm{eff}} \geq 60$kK) known WDs brighter…
We present the results of a search for diffuse x-ray sources in a 65 ksec ROSAT PSPC exposure of 47 Tuc. There is faint, soft emission on the NE side of the cluster at a distance of 6 arcmin from the core. The location of this emission…
We have obtained optical spectra of seven stars in the old galactic cluster M67 that are unusual sources of X-rays, and investigate whether the X-ray emission is due to magnetic activity or to mass transfer. The two binaries below the giant…
We report on the results of the first XMM-Newton satellite observation of the luminous and helium-rich O-type subdwarf BD +37{\deg} 1977 carried out in April 2014. X-ray emission is detected with a flux of about 4*10^(-14) erg/cm2/s…
We present deep K-band imaging at the positions of four very faint X-ray sources found in the UK ROSAT Deep Survey to have no optical counterpart brighter than R~23. Likely identifications are found within the ROSAT error circle in all four…
The quiescent emission of the anomalous X-ray pulsar (AXP) 4U 0142+61 extends over a broad range of energy, from radio up to hard X-rays. In particular, this object is unique among soft gamma-ray repeaters (SGRs) and AXPs in presenting…
As a part of the ISOPHOT CIRB (Cosmic Infrared Background Radiation) project we have searched for point-like sources in eight fields mapped at two or three wavelengths between 90 and 180um. Most sources are previously unknown and based on…
The second IBIS/ISGRI survey has produced a catalogue containing 209 hard X-ray sources visible down to a flux limit of around 1 milliCrab. The point source location accuracy of typically 1-3 arcminutes has allowed the counterparts for most…
The ROSAT PSPC pulse height spectrum of the peculiar He-rich hot white dwarf KPD 0005+5106 provided a great surprise when first analysed by Fleming, Werner & Barstow (1993). It defied the best non-LTE modelling attempts in terms of…