Related papers: Origin of the Hard X-ray Emission from the Galacti…
Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l,b) ~ (28.5, 0.0), where no discrete X-ray source had been reported previously.…
Similarly to the larger Galactic ridge, the Galactic center region presents a hard diffuse emission whose origin has been strongly debated for the past two decades: does this emission result from the contribution of numerous, yet…
We review highlights of the results obtained from recent Galactic X-ray survey observations, in particular ASCA Galactic center and plane survey and our Chandra deep survey on the (l,b)=(28.5,0) region. Strong hard X-ray diffuse components…
Apparently diffuse X-ray emission has been known to exist along the central quarter of the Galactic Plane since the beginning of the X-ray astronomy, which is referred to as the Galactic Ridge X-ray emission (GRXE). Recent deep X-ray…
An unresolved X-ray glow (at energies above a few kiloelectronvolts) was discovered about 25 years ago and found to be coincident with the Galactic disk -the Galactic ridge X-ray emission. This emission has a spectrum characteristic of a…
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…
Using the Chandra ACIS-I instruments, we have carried out a deep X-ray observation on the Galactic plane region at (l,b) ~ (28.5, 0.0), where no discrete X-ray sources have been known previously. We have detected, as well as strong diffuse…
We analyzed deep Chandra observations of the Galactic plane region centered at l=28.55, b=-0.03 with the aim to obtain the best possible constraints on the contribution of weak point sources to the Galactic ridge X-ray emission (GRXE) in…
The origin of the Galactic center diffuse X-ray emission (GCDX) is still under intense investigation. We have found a clear excess in a longitudinal GCDX profile over a stellar number density profile in the nuclear bulge region, suggesting…
Galactic X-ray emission is a manifestation of various high-energy phenomena and processes. The brightest X-ray sources are typically accretion-powered objects: active galactic nuclei and low- or high-mass X-ray binaries. Such objects with…
We present results of a study of the Galactic ridge X-ray emission (GRXE) in hard X-rays performed with the IBIS telescope aboard INTEGRAL. The imaging capabilities of this coding aperture telescope make it possible to account for the flux…
Detailed spectral analysis of the Galactic X-ray background emission, or the Galactic Ridge X-ray Emission (GRXE), is presented. To study the origin of the emission, broad-band and high-quality GRXE spectra were produced from 18 pointing…
A recent re-determination of the non-thermal component of the hard X-ray to soft gamma-ray emission from the Galactic ridge, using the SPI instrument on the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) Observatory, is shown to…
We analyse new results of Chandra and Suzaku which found a flux of hard X-ray emission from the compact region around Sgr A$^\ast$ (r ~ 100 pc). We suppose that this emission is generated by accretion processes onto the central supermassive…
Using the Chandra ACIS-I instruments, we have carried out the deepest X-ray observation on a typical Galactic plane region at l 28.5 deg, where no discrete X-ray sources have been known previously. We have detected, as well as strong…
(Abridged) The diffuse X-ray emission from the thin disk surrounding the Galactic mid-plane (the so-called Galactic ridge) was measured with RXTE PCA in order to determine the spatial extent, spectral nature, and origin of the emission.…
Diffuse 511 keV line emission, from the annihilation of cold positrons, has been observed in the direction of the Galactic Centre for more than 30 years. The latest high-resolution maps of this emission produced by the SPI instrument on…
We present the first results from the \xmm Galactic Plane Survey (XGPS). In the first phase of the programme, 22 pointings were used to cover a region of approximately three square degrees between 19\deg -- 22\deg in Galactic longitude and…
We study a possible connection between different non-thermal emissions from the inner few parsecs of the Galaxy. We analyze the origin of the gamma-ray source 2FGL J1745.6-2858 (or 3FGL J1745.6-2859c) in the Galactic Center and the diffuse…
The Galactic Center is a prominent source in X-rays and gamma-rays and the study of its high-energy emission is crucial in understanding the physical phenomena taking place in its dense and extreme environment, phenomena that are possibly…