The Galactic Center region viewed by H.E.S.S

TL;DR

H.E.S.S. observations of the Galactic Center reveal detailed VHE gamma-ray emissions, including a steady source at Sgr A* and diffuse emission along the Galactic Plane, providing insights into energetic particle processes near the Milky Way's core.

Contribution

This paper presents the first detailed VHE gamma-ray view of the Galactic Center region, including the detection of a steady source at Sgr A* and diffuse emission, enhancing understanding of high-energy processes.

Findings

Detection of a steady gamma-ray source at Sgr A*

Identification of diffuse emission along the Galactic Plane

Diffuse emission may dominate the highest energy spectrum

Abstract

The Galactic center region is the most active region in the Milky Way harboring a wealth of photon sources at all wavelengths. H.E.S.S. observations of the Galactic Center (GC) region revealed for the first time in very high energy (VHE, E> 100 GeV) gamma-rays a detailed view of the innermost 100 pc of the Milky Way and provided a valuable probe for the acceleration processes and propagation of energetic particles near the GC. H.E.S.S. has taken more than 180 hours of good-quality observations toward the GC region since the experience started in 2003. A strong and steady gamma-ray source has been detected coincident in position with the supermassive black hole Sgr A*. Besides the central pointlike source, a diffuse emission extended along the Galactic Plane has been detected within about 1$^{\circ}$ around the GC. An accurate analysis of the Galactic center region suggests that the diffuse emission may dominate highest energy end of the overall GC source spectrum. I will review the current VHE view by H.E.S.S. of the GC region and briefly discuss the theoretical models which explain VHE gamma-ray emissions of the central source and the diffuse emission.