High energy astronomy program at UCSD

Abstract

The High Energy Astronomy program at UCSD consists of several elements, including laboratory development of detector systems, balloon flights to test detector concepts and to make basic observations of cosmic sources, space flights to make extended observations at high sensitivity, and data analysis. Since the start of the group in 1962, over 70 balloon flights have been made, mostly through the U.S. National Scientific Balloon Facility. Many of these flights were determine detector properties and background in the radiation environment at about 130,000 ft (40 km or 3 gm/cm 2 depth), which is essentially the same as on a spacecraft in low earth orbit. Many fundamental observations have also been obtained, including spectral and time variations of X-ray sources over the 25–200 keV range, imaging of the Crab Nebula in hard X-rays, and detection of an extremely hot component in solar flares. More recently, efforts have been concentrated on obtaining high resolution (E/ ΔE ≈ 300) observations of solar and cosmic gamma-rays in the 20 keV to 10 MeV range. The program, which involves faculty and research staff, graduate students, and technical support personnel will be described.