William T. Reach

(1) COMETS have been called "frozen mudballs" and "dirty snowballs"... which description is more accurate? I am studying the solid material produced by comets using infrared and optical observations of their debris trails. These debris trails are the same things as meteor storms; we can look for debris trails from any comet we want to, while meteor storms only happen for comets that pass close to the Earth's orbit. We are using SIRTF and Palomar observatories for this study.

(2) SUPERNOVAE due to massive stars often occur near molecular clouds. With Jeonghee Rho, I am involved in a search for the impacts of supernova blast waves on molecular clouds, using near-infrared H2 imaging from Palomar, mm-wave spectroscopy, and eventually SIRTF observations.

(3) THE COSMIC INFRARED BACKGROUND is the integrated light from energy production including nucleosynthesis (stars and galaxies) and other processes. With the Great Observatories Origins Deep Survey (GOODS) team, and postdoctoral researcher Ranga-Ram Chary in particular, I will use ultra-deep source counts to measure the resolvable (galaxian) contribution to the cosmic background and to see if there is any left over for other processes, as we inferred in the near infrared.