Galactic Particle Accelerators and a Pointing Monitor for VERITAS

University Of Iowa, Iowa City IA

Investigators

Abstract

Our Galaxy contains astrophysical systems which accelerate particles to energies beyond the reach of any accelerator built by humans. What drives these accelerators is a major question in astrophysics and understanding these accelerators has broad implications. The most energetically important Galactic particle accelerators are the sources of cosmic rays. Cosmic rays contain at least as much energy as the other phases of the interstellar medium (ISM). Yet, their origin is still uncertain, 94 years after their discovery. Identifying the process or processes which accelerate highly energetic cosmic ray particles is key to understanding the full energy budget of the ISM. Observations in the TeV band are a sensitive probe of physical processes occurring in a variety of Galactic objects. Detection of, or sensitive upper limits on, TeV emission from supernova remnants should resolve the long-standing question of whether hadronic cosmic rays are accelerated in supernova remnants. Measurement of the TeV spectra from inverse-Compton emission in pulsar-powered nebulae should permit determination of the nebular magnetic fields and lead to constraints on the energetics of pulsar winds. Observation of TeV gamma-rays from the jets of accreting stellar-mass black holes should lead to important information about the jet production mechanism. Under this proposal, the Very Energetic Radiation Imaging Telescope Array System (VERITAS), a ground-based TeV telescope array, will be used to study gamma-ray sources. A pointing monitor will be constructed to improve their knowledge of the pointing of the telescopes to enable source localization and mapping of diffuse emission to the limiting accuracy permitted by the gamma-ray reconstruction. The pointing monitor will enhance all aspects of VERITAS science, and particularly the identification of new unidentified gamma-ray sources and the mapping of extended sources such as supernova remnants. An integral part of the proposed activity will be the broad dissemination of information on very high energy gamma-ray astronomy and development of demonstrations targeted for school children illustrating concepts in optics as part of the VERITAS education and outreach program being led by the Adler Planetarium and Astronomy Museum. The materials developed will be used in local education and public outreach efforts including "Family Adventures in Science" and "Hawk-Eyes on Science" and for elementary school classroom visits by the PI. These activities should benefit society by increasing understanding of science and astronomy.