Alice Harding, NASA Goddard Space Flight Center

The Maryanne Shelley Jessup MacConochie Colloquium

Uncovering Secrets of Pulsars With the Fermi Gamma-Ray Space Telescope

Of the several thousand pulsars that have been discovered by radio telescopes over the past forty year, only a handful were known to emit gamma-ray pulsations before the launch in June, 2008 of the Fermi Gamma-Ray Space Telescope. After three years of operation, nearly 100 gamma-ray pulsars have been detected and several new populations have been discovered. For the first time, pulsars are being discovered through their gamma-ray pulsations alone. The pulsations had not been seen before at any other wavelength but are coming from the locations of many previously unidentified Galactic gamma-ray sources. Millisecond pulsars have been confirmed as powerful sources of gamma-ray emission, and a whole population of these objects is seen with Fermi both in the Galactic plane and in globular clusters. From these new discoveries, we have learned that the gamma rays are not emitted in narrow "lighthouse" beams but in very large fan beams that can be seen from virtually all directions. Gamma-ray observations may thus provide a unique capability to understand the physics of pulsars and to uncover hidden neutron stars that are the compact remnants of supernova explosions.

Host:  Dong Lai & Richard Lovelace