Catching gamma rays with a LHAASO
What are PeVatrons and how do we find them?
What are PeVatrons and how do we find them?
Today’s paper explores the origin of unexpected gamma-rays in our Galaxy.
Today we’re talking about the history of gamma-ray astrophysics, starting with a very important observation from the late 1980s
If dark matter particles can collide to release gamma-rays, the best place to see them will be in the centers of dwarf galaxies. Archival Fermi-LAT images around Reticulum 2 show the first ever detection of gamma-rays from a dwarf galaxy. Dark matter detection may be close at hand!
Cosmic rays hit the Earth and produce showers of particles that can be detected on the ground. Understanding where these cosmic rays come from can help scientists pin down their sources and construct models for the magnetic field in our neighborhood.
Dark matter is not so dark as the name might imply. Although it so far refuses to interact with normal matter via any force other than gravity, there are secondary signals that we can detect. When we turn our gamma-ray telescopes on regions like the Galactic Center that contain a high density of dark matter, we expect to see a dim, widespread gamma ray haze coming from seemingly empty space, with no baryonic matter source. This paper, due to be published by the Astrophysical Journal, discusses the search for this signature by the collection of satellites that surrounds the Milky Way, and uses the lack of a detection to set an upper limit on the cross-section of the WIMP particle.