Related papers: The puzzling symbiotic X-ray system 4U1700+24

4U0114$+$65 is one of the slowest known X-ray pulsars. We present an analysis of a pointed observation by the XMM-Newton X-ray telescope. The energy-resolved light curve, the time-resolved X-ray spectra provided by the EPIC cameras on board…

The relatively small family of ultra-compact X-ray binary systems is of great interest for many areas of astrophysics. We report on a detailed X-ray spectral study of the persistent neutron star low mass X-ray binary 1RXS J170854.4-321857.…

A puzzling variety of superorbital modulations have been discovered in several supergiant High-Mass X-ray binaries (sgHMXBs). To investigate the mechanisms driving these superorbital modulations, we have analyzed long-term Neil Gehrels…

Rossi X-ray Timing Explorer All-Sky Monitor observations of the X-ray source 4U2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of approximately 9.6 days. If the modulation is due to…

We present the results obtained from broadband spectroscopy of the high mass X-ray binary 4U 1700-37 using data from a Suzaku observation in 2006 September 13-14 covering 0.29-0.72 orbital phase range. The light curves showed significant…

Here we report the detection of a 626 s periodic modulation from the X-ray source 2XMM J174016.0-290337 located in the direction of the Galactic center. We present temporal and spectral analyses of archival XMM-Newton data and photometry of…

U 2206+54 is a wind-fed high mass X-ray binary with a main-sequence donor star. The nature of its compact object was recently identified as a slow-pulsation magnetized neutron star. INTEGRAL/IBIS observations have a long-term hard X-ray…

We present optical spectroscopy of several (candidate) ultra-compact X-ray binaries (UCXBs) obtained with the ESO VLT and Gemini-North telescopes. In only one of five observed UCXB candidates did we find evidence for H in its spectrum (4U…

In this study, we examine 51 archival NICER observations and 6 archival NuSTAR observations of the neutron star (NS) ultra-compact X-ray binary (UCXB) 4U 0614+091, which span over 5 years. The source displays persistent reflection features,…

Low-mass X-ray binary systems consist of a neutron star and a main-sequence companion star. The compact object accretes matter via Roche-lobe overflow, which leads to an accretion disk. In addition to a broad-band continuum emission of a…

We report the detection, with ${\it Chandra}$ and XMM-${\it Newton}$, of faint, soft X-ray emission from four symbiotics stars that were not known to be X-ray sources. These four object show a $\beta$-type X-ray spectrum, i.e. their spectra…

We present the results of a study with the \emph{Swift} Burst Alert Telescope in the 14 -- 195 keV range of the long-term variability of 5 low mass X-ray binaries with reported or suspected super-orbital periods -- 4U 1636-536, 4U 1820-303,…

The peculiar low mass X-ray binary XSSJ12270-4859, associated with the Fermi/LAT source 2FGLJ1227.7-4853, was in a X-ray, gamma-ray and optical low-luminosity persistent state for about a decade until the end of 2012, when it has entered…

Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact…

We have discovered a new X-ray emitting compact binary that is the likely counterpart to the unassociated Fermi-LAT GeV $\gamma$-ray source 4FGL J1120.0-2204, the second brightest Fermi source that still remains formally unidentified. Using…

An overview of the results of observations for the transient X-ray pulsar 4U 0115+63, a member of a binary system with a Be star, since its discovery to the present day (~40 years) based on data from more than dozen observatories and…

We analyzed multiwavelength observations of the previously identified Galactic center X-ray binary CXO 174528.79-290942.8 (XID 6592) and determine that the near-infrared counterpart is a red supergiant based on its spectrum and luminosity.…

Thanks to the high sensitivity of the instruments on board the XMM-Newton and Chandra satellites, it has become possible to explore the properties of the X-ray emission from hot subdwarfs. The small but growing sample of hot subdwarfs…

The X-ray binary 4U 1954+31 has been classified as a Low Mass X-ray Binary (LMXB) containing a M giant and a neutron star (NS). It has also been included in the rare class of X-ray symbiotic binaries (SyXB). The Gaia parallax, infrared…

We report the discovery using data from the Swift Burst Alert Telescope (BAT) of superorbital modulation in the wind-accretion supergiant high-mass X-ray binaries 4U 1909+07 (= X 1908+075), IGR J16418-4532, and IGR J16479-4514. Together…