Fermi Gamma-ray Space Telescope: High-Energy Results from the First Year

TL;DR

The Fermi Gamma-ray Space Telescope's first-year results include discoveries of diverse gamma-ray sources, new insights into gamma-ray bursts, and precise measurements of cosmic-ray spectra, advancing high-energy astrophysics understanding.

Contribution

This paper presents the first-year high-energy observations from Fermi LAT, revealing new source characteristics, gamma-ray burst properties, and cosmic-ray measurements not previously available.

Findings

Detected numerous gamma-ray sources including active galaxies and pulsars.

Uncovered surprising high-energy emission features in gamma-ray bursts.

Measured cosmic-ray electron and positron spectra with high precision.

Abstract

The Fermi Gamma-ray Space Telescope (Fermi) was launched on June 11, 2008 and began its first year sky survey on August 11, 2008. The Large Area Telescope (LAT), a wide field-of-view pair-conversion telescope covering the energy range from 20 MeV to more than 300 GeV, is the primary instrument on Fermi. While this review focuses on results obtained with the LAT, the Gamma-ray Burst Monitor (GBM) complements the LAT in its observations of transient sources and is sensitive to X-rays and gamma-rays with energies between 8 keV and 40 MeV. During the first year in orbit, the Fermi LAT has observed a large number of sources that include active galaxies, pulsars, compact binaries, globular clusters, supernova remnants, as well as the Sun, the Moon and the Earth. The GBM and LAT together have uncovered surprising characteristics in the high-energy emission of gamma-ray bursts (GRBs) that have been used to set significant new limits on violations of Lorentz invariance. The Fermi LAT has also made important new measurements of the Galactic diffuse radiation and has made precise measurements of the spectrum of cosmic-ray electrons and positrons from 20 GeV to 1 TeV.