GLAST Large Area Telescope Multiwavelength Opportunities

Abstract

Abstract. High-energy gamma-ray sources are inherently nonthermal, multiwavelength objects. With the launch of the Gamma-ray Large Area Space Telescope (GLAST) scheduled for later this year, the GLAST Large Area Telescope (LAT) Collaboration invites cooperative efforts from observers at all wavelengths. Among the many topics where multiwavelength studies will maximize the scientific understanding, two stand out for particular emphasis: (1) Active Galactic Nuclei. The study of AGN gamma-ray jets through time variability and spectral modeling can help link the accretion processes close to the black hole with the large-scale interaction of the AGN with its environment; (2) Unidentified Gamma-ray Sources. New gamma-ray sources need first to be identified with known objects seen at other wavelengths using position, spectrum, or time variability, and then multiwavelength studies can be used to explore the astrophysical implications of high-energy radiation from these sources. Observers interested in any type of coordinated observations should contact the LAT Multiwavelength Coordinating Group. THE VALUE OF MULTIWAVELENGTH STUDIESAs can be seen in Figure 1, all known classes of high-energy gamma-ray sources are multiwavelength objects, with emission seen across much of the electromagnetic spectrum. Because astrophysical gamma rays are produced by nonthermal processes involving high-energy particles, a broad spectral range is expected.

Observations of the BL Lacertae Object 3C 66A with STACEE

“…The possibility that there may be detectable flux at energies near 100 GeV makes 3C 66A an interesting target for the new generation of imaging Cerenkov telescopes such as VERITAS and MAGIC. Together with GLAST (Thompson et al 2004) and AGILE (Pittori et al 2004) at lower energies, observations of this source will provide a comprehensive data set at sub-TeV gamma-ray energies that will be important for modeling studies.…”