Fermi Gamma-ray Space Telescope

Multiwavelength Observing - Support Programs

A number of observing programs have been established to provide either regular monitoring or targeted observations specifically designed to help support the Fermi science effort. Many of the programs listed below provide their datasets publicly as a service to the science community. These data are not part of the Fermi public dataset, so their use should be coordinated directly with the project leads. Please refer to each site for data usage and/or attribution information. We note that some of these resources, such as several of the Blazar Monitoring campaigns and the Pulsar Ephemerides database have not been continuously maintained over the full Fermi mission. For more information on coordinated observations with the LAT, please contact the LAT Multiwavelength Coordinating Group.

Blazar Monitoring

Pulsar Timing Observations

The Fermi LAT Pulsar Timing Consortium (PTC) was formed before launch to organize regular radio and X-ray timing of over 200 pulsars to ensure that accurate and contemporaneous ephemerides are available for folding the LAT gamma-ray data to search for gamma-ray pulsations. This work is described by Smith, et al. (2008), and Weltevrede, et al. (2010). For energetic young pulsars, frequent monitoring is required to maintain phase connection in the presence of strong timing noise and glitches, so this work is of critical importance to the LAT science mission. Ephemerides and radio profiles used in published Fermi results have been made available through the FSSC. Since its inception, the PTC has expanded to timing of a sampling of pulsar from all parts of the period derivative vs period plane, to take advantage of Fermi's all-sky coverage to search for emission from unexpected pulsar categories.

  • PSRPI (PulSaR Parallax Interferometry)
    Multi-epoch astrometric observations of a sample of Fermi-detected radio pulsars with the VLBA in order to obtain model-independent estimates of their velocity and distance. These measurements help enable precise comparisons of spin-down power and gamma-ray luminosity for the neutron stars, probe their birth sites and relativistic winds, help refine Galactic electron density models, and enable more stringent tests of theories of gravity. (More pulsar parallaxes)

Pulsar Search Observations

The Fermi LAT Pulsar Search Consortium (PSC) is a partnership between the LAT team and pulsar searchers using radio telescopes around the world to search for new radio pulsars associated with LAT gamma-ray sources uncovered in Fermi observations. These searches have been highly productive, discovering several young pulsars (one of which is a LAT gamma-ray pulsar, Camilo et al. (2000)) and 56 millisecond pulsars (MSPs). The millisecond pulsars are distributed approximately uniformly across the sky, providing a significant number of new pulsars that have been added to pulsar timing array projects, such as NANOGrav, increasing their sensitivity to gravitational waves. The new MSPs also include an unexpectedly large number of interacting and eclipsing binary systems, known as black widows and redbacks, which are shedding new light on the formation and evolution of millisecond pulsars in X-ray binaries. A review of the PSC work can be found in Ray et al. (2012).