M82 is a bright galaxy located approximately 12 million light years from Earth, in the direction of the Ursa Major constellation. In the active starburst region at its center, stars are being formed at a rate approximately ten times more rapidly than in entire "normal" galaxies like our own Milky Way. The cosmic rays produced in the formation, life and death of the massive stars in this region eventually produce diffuse gamma-ray emission via their interactions with interstellar gas and radiation. Due to its unusually high cosmic-ray and gas densities and its relative proximity, M82 is expected to be the brightest starburst galaxy in VHE gamma rays.

Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

The VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a collection of four 12-meter Cherenkov telescopes used to detect astrophysical sources of very-high-energy gamma rays. VERITAS continues the tradition of the 10-m telescope and is also located at the Fred Lawrence Whipple Observatory (FLWO). It is comprised of an array of four 12-meter (39 feet) diameter Cherenkov telescopes. VERITAS began full-scale observations in September 2007. The telescopes are used to study the remnants of exploded stars, distant galaxies, powerful gamma ray bursts, and to search for evidence of mysterious dark matter particles.

Credit: N. Galante

The false-color figure taken from the study "A connection between star formation activity and cosmic rays in the starburst galaxy M82," shows the very high energy gamma-ray emission observed by VERITAS. The black star is the location of the active starburst region. The emission from M82 is effectively point-like for VERITAS and the white circle indicates the size of a simulated point-source. The entire galaxy would be contained within the circle.

Credit: VERITAS

VERITAS, is operated by a collaboration of more than 100 scientists from 22 different institutions in the United States, Ireland, England and Canada. VERITAS is funded by the U.S. Department of Energy, the U.S. National Science Foundation, the Smithsonian Institution, the Natural Sciences and Engineering Research Council of Canada, the Science Foundation Ireland and the STFC of the U.K.

Credit: VERITAS