The progresses and prospects of high-energy gamma-ray observations

Abstract

The high energy gamma-ray emission is the high end of the cosmic electromagnetic radiation. It is associated with the huge energy release, relativistic particle acceleration and the corresponding non-thermal emission processes within the cosmic objects. High energy gamma-ray astronomy is an important window to explore physical processes under extreme conditions in the universe, and is also a power tool to study the origin of cosmic rays, a century puzzle. Thanks to the successful operation of a new generation of gamma-ray detectors, both space-based and ground-based gamma-ray detectors have achieved fruitful results. At energy above 100 MeV, satellite detector Fermi has increased the number of gamma-ray sources from about 300 to more than 3000 since 2008. At energy above 100 GeV, the ground-based Cherenkov telescopes, HESS, MAGIC, VERITAS, and EAS arrays, Tibet AS<italic>γ</italic>, Milagro, ARGO-YBJ, have also increased the number of gammaray sources from about 10 to more than 160 since 2003. At the same time, the next generation of ground-based detectors, CTA and LHAASO, are also steadily pushed forward, which will boost the sensitivity of current detectors at least up to 10 times. This article will review the current status of each gamma-ray experiment and their observation progresses on gamma-ray sources including pulsar and its wind nebula, supernova remnant, gamma-ray binary system, active galactic nuclei, GRB and so on. The potential prospects of future projects CTA and LHAASO are also discussed.