University of Maryland, College Park | 2020 Jan 14
Nine sources of extremely high-energy gamma rays have been identified in a new catalog compiled by researchers with the High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, including nine University of Maryland physicists. All nine sources produce gamma rays with energies over 56 trillion electron volts (TeV)—more than eight times the energy of the most powerful proton beams produced at particle accelerators on Earth—and three emit gamma rays extending to 100 TeV and beyond, making these the highest-energy sources ever observed in our galaxy. The catalog helps to explain where the particles originate and how they are produced with such extreme energies.
“The very high-energy gamma rays we detect are produced by interactions of even higher energy charged particles near their source,” said Jordan Goodman, a Distinguished University Professor of Physics at UMD and U.S. lead investigator and spokesperson for the HAWC collaboration. “Charged particles are bent in the magnetic fields of our galaxy and don’t point back to their origin. Gamma rays, like light, travel in straight lines allowing us to use them to map the sources of the high-energy emission. HAWC, which is a wide field-of-view instrument, views the overhead sky 24/7 giving us a deep exposure to look for the rare high energy gamma ray events.”
The catalog of high-energy sources was published online in the journal Physical Review Letters on Jan. 15, 2020. Higher-energy astrophysical particles have previously been detected, but this is the first time specific galactic sources have been pinpointed for such high-energy particles. All of the sources have extremely energetic pulsars nearby. The number of sources detected may indicate that ultra-high-energy emission is a generic feature of powerful particle winds coming from pulsars embedded in interstellar gas clouds known as nebulae, and that more detections will be forthcoming. ...
Multiple Galactic Sources with Emission Above 56 TeV Detected by HAWC ~ A. U. Abeysekara et al (HAWC Collaboration)
- Physical Review Letters 124(2):1102 (17 Jan 2020) DOI: 10.1103/PhysRevLett.124.021102
- arXiv.org > astro-ph > arXiv:1909.08609 > 18 Sep 2019 (v1), 09 Jan 2020 (v2)