The Gamma-ray Sky with Fermi

TL;DR

This paper reviews four years of Fermi Gamma-ray Space Telescope observations, highlighting discoveries of gamma-ray transients, persistent sources, and constraints on fundamental physics and dark matter models.

Contribution

It provides a comprehensive overview of the Fermi telescope's findings, including new gamma-ray sources and limits on physics beyond the Standard Model.

Findings

Stringent limit on Lorentz invariance violation from gamma-ray burst

Unexpected gamma-ray variability from the Crab Nebula

Discovery of a large gamma-ray structure near the Galactic Center

Abstract

Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as clusters of galaxies. Some results include a stringent limit on Lorentz invariance violation derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure in the direction of the center of our Galaxy, and strong constraints on some Weakly Interacting Massive Particle (WIMP) models for dark matter.