Related papers: Disentangling the Galactic centre X-ray reflection…
We exploit XMM-Newton archival data in a study of the extended X-ray emission emanating from the Galactic Centre (GC) region. EPIC-pn and EPIC-MOS observations, with a total exposure approaching 0.5 and 1 Ms respectively, were used to…
Strong iron fluorescence at 6.4 keV and hard-X-ray emissions from giant molecular clouds in the Galactic center region have been interpreted as reflections of a past outburst of the Sgr A* supermassive black hole. Careful treatment of…
In X-rays, the Galactic Centre (GC) Region appears as a complex of diffuse thermal and non-thermal X-ray emission intermixed with a population of luminous discrete sources. Here we present some new findings from the XMM-Newton GC survey,…
The origin of the X-ray emission from the central region of the Galaxy has remained a mystery, despite extensive study over the past two decades. A fundamental question is the relative contribution of the point-source and diffuse components…
Diffuse X-rays from the Galactic center (GC) region were found to exhibit many K-shell lines from iron and nickel atoms in the 6--9 keV band. The strong emission lines seen in the spectrum are neutral iron K$\alpha$ at 6.4~keV, He-like iron…
The Nuclear Stellar Disk (NSD), together with the Nuclear Stellar Cluster and the supermassive black hole Sgr A*, forms the central region of the Milky Way. Galactic X-ray background emission is known to be associated with the old stellar…
A mosaic of 7 ROSAT PSPC pointed observations in the direction of (l,b ~ 10,0 deg) reveals deep X-ray shadows in the 0.5-2.0 keV band cast by dense molecular gas. The comparison between the observed on-cloud and off-cloud X-ray fluxes…
(Abridged) The inner couple hundred pcs of our Galaxy is characterized by significant amount of synchrotron-emitting gas, which appears to co-exist with a large reservoir of molecular gas. The spatial correlation between fluorescent Fe…
Over the last 3 yrs, the Galactic center (GC) region has been monitored with the Chandra X-Ray Observatory. With 11 Chandra observations through 2002 June, the total effective exposure reaches ~590 ks, providing significant photon…
The Galactic center region near l$\approx0.2^0$ hosts a mixture of nonthermal linear filaments and thermal radio continuum features associated with the radio Arc. Chandra observations of this region reveal an X-ray filament and diffuse…
We use Chandra deep observations of the Galactic Center (GC) region to improve the constraints on the unresolved fraction of the Galactic X-ray background (also known as the Galactic ridge X-ray emission). We emphasize the importance of…
We report the discovery by XMM-Newton and Chandra of a hard extended X-ray source (XMM J174540-2904.5) associated with a compact non-thermal radio filament (the Sgr A-E `wisp'=1LC 359.888-0.086= G359.88-0.07), which is located within ~4…
Past studies have identified a spatially extended excess of $\sim$1-3 GeV gamma rays from the region surrounding the Galactic Center, consistent with the emission expected from annihilating dark matter. We revisit and scrutinize this signal…
We conduct a comprehensive search for X-ray emission lines from sterile neutrino dark matter, motivated by recent claims of unidentified emission lines in the stacked X-ray spectra of galaxy clusters and the centers of the Milky Way and…
We study the two dimensional surface brightness distribution of the Galactic X-ray background emission outside the central degree around Sgr A* in the 6.7 keV line as measured by the PCA spectrometer of the RXTE observatory. The use of the…
Reliable identification of the origin of the high-energy non-thermal emission from the Galactic Center (GC) is not achievable without adequate consideration of the ambient conditions such as the magnetic field configuration or gas…
We study the full-sky distribution of the radio emission from the stimulated decay of axions which are assumed to compose the dark matter in the Galaxy. Besides the constant extragalactic and CMB components, the decays are stimulated by a…
We study the hard X-ray (20-100 keV) variability of the Galactic Center (GC) and of the nearby sources on the time scale of 1000 s. We find that 3 of the 6 hard X-ray sources detected by INTEGRAL within the central 1 degree of the Galaxy…
We analyse the 6.4 keV iron line component produced in the Galactic Center (GC) region by cosmic rays in dense molecular clouds (MCs) and in the diffuse molecular gas. We showed that this component, in principle, can be seen in several…
The diffuse Fe XXV (6.7 keV) line emission observed in the Galactic ridge is widely accepted to be produced by a superposition of a large number of unresolved X-ray point sources. In the very central degrees of our Galaxy, however, the…