Related papers: Non-Thermal Radiation from the Inner Galaxy
The presence of dark matter (DM) is suggested by a wealth of astrophysical and cosmological measurements. However, its underlying nature is yet unknown. Among the most promising candidates are weakly interacting massive particles (WIMPs):…
Growing supermassive black holes (Active Galactic Nuclei; AGN) release energy with the potential to alter their host galaxies and larger-scale environment; a process named "AGN feedback". Feedback is a required component of galaxy formation…
The nonthermal characteristics of starburst galaxies and galaxy clusters are reviewed and the perspectives for their observation in high energy gamma rays discussed. It is argued that starburst galaxies should have physically similar and…
The massive Galactic black hole and the stars around it are a unique laboratory for studying how relaxation processes lead to close interactions of stars and compact remnants with the central massive black hole, in particular those leading…
Gamma-ray emission from large structures is useful for tracing the propagation and distribution of cosmic rays throughout our Galaxy. For example, the search for gamma-ray emission from Giant Molecular Clouds may allow us to probe the flux…
Recent IceCube results suggest that the first detection of very high energy astrophysical neutrinos have been accomplished. We consider these results at face value in a Galactic origin context. Emission scenarios from both the Fermi bubble…
We report on sensitive dual-frequency (1.7 and 5 GHz) European VLBI Network observations of the central region of nine Seyfert galaxies. These sources are among the faintest and least luminous members of a complete sample of nearby (d<22…
The Galactic center lobe (GCL) is a $\sim 1^\circ$ object located north of the Galactic center. In the mid-infrared (MIR), the GCL appears as two 8.0-micron filaments that roughly define an ellipse. There is strong 24-micron and radio…
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,…
Recently, a spatially extended excess of gamma rays collected by the Fermi-LAT from the inner region of the Milky Way has been detected by different groups and with increasingly sophisticated techniques. Yet, any final conclusion about the…
The Galactic center (GC) provides a unique laboratory for a detailed examination of the interplay between massive star formation and the nuclear environment of our Galaxy. Here, we present an 100 ks Chandra ACIS observation of the Arches…
The strongest experimental evidence for dark matter is the Galactic Center gamma-ray excess observed by the Fermi telescope and even predicted prior to discovery as a potential dark matter signature via WIMP dark matter self-annihilations.…
The Galactic Center is the closest galactic nucleus that allows us to determine the multi-frequency behavior of the supermassive black hole counterpart Sagittarius A* in great detail. We put SgrA*, as a nucleus with weak activity, into the…
We study the survival of ultrahigh energy nuclei injected in clusters of galaxies, as well as their secondary neutrino and photon emissions, using a complete numerical propagation method and a realistic modeling of the magnetic, baryonic…
Because of its nearness to Earth, the centre of the Milky Way is the only galaxy nucleus in which we can study the characteristics, distribution, kinematics, and dynamics of the stars on milli-parsec scales. We have accurate and precise…
Extended warm and cold gas nebulae, with complex morphologies and kinematics, have been observed in the centres of cool-core galaxy clusters. Their origin within the hot intracluster medium (ICM) is still puzzling, and among many…
Particle dark matter near the galactic center is accreted by the central black hole into a dense spike, strongly enhancing its annihilation rate. Searching for its annihilation products may give us information on the presence or absence of…
Capture and tidal disruption of stars by the supermassive black hole in the Galactic center (GC) should occur regularly. The energy released and dissipated by this processes will affect both the ambient environment of the GC and the…
Observations using the Fermi Large Area Telescope (Fermi-LAT) have found a significant gamma-ray excess surrounding the center of the Milky Way (GC). One possible interpretation of this excess invokes gamma-ray emission from an undiscovered…
After discovery of the Fermi bubbles, giant structures observed in radio to X-rays have been discussed as possi- ble evidence of past activities in the Galactic Center (GC). We report here on the analysis of Suzaku data pointing around the…