Discovery of VHE gamma-ray emission from the W49 region with H.E.S.S

Understand

The W49 region hosts two bright radio sources: the star forming region W49A and the supernova remnant W49B.

• The 10^6 M_odot Giant Molecular Cloud W49A is one of the most luminous giant radio HII regions in our Galaxy and hosts several active, high-mass star formation sites.
• The mixed-morphology supernova remnant W49B has one of the highest surface brightness in radio of all the SNRs of this class in our Galaxy and is one of the brightest ejecta-dominated SNRs in X-rays.
• Infrared observations evidenced that W49B is interacting with molecular clouds and Fermi recently reported the detection of a coincident bright, high-energy gamma-ray source.