Research Interests

• Sloan Digital Sky Survey
• ISM in galaxies
• Mass loss from evolved stars
• Observational studies of the ISM
• Galactic structure

1. Sloan Digital Sky Survey

   I'm working on the construction and planning of this major project, primarily in the areas of software oversight, science planning and proposal writing. Princeton is responsible for the 54-CCD mosaic camera and the photometric pipeline which reduces the data.

2. ISM in Galaxies

   I do observational studies of the interstellar medium in galaxies, primarily early-type galaxies. I have a large program on the Infrared Space Observatory to observe far infrared emission from dust in elliptical galaxies. I've also done several studies using the IRAS data, including work on the mean cold ISM content and star formation rates in elliptical and in powerful radio galaxies.

3. Mass Loss from Evolved Stars

   The large circumstellar envelopes produced by mass loss from evolved red giant stars can be observed in molecular line emission and via infrared emission from circumstellar dust. I do line and continuum work with the submillimeter telescopes on Mauna Kea and some work with the VLA and IRAS. We've found very fast (200 km/s) molecular winds from some stars, which accompany (and prehaps cause) the beginning evolution to the planetary nebula stage. We've found that many stars have more than one wind, and that this appears to accompany evolutionary changes. Much of the galactic dust, and most of the carbon, appears to come from these stars.

Selected Bibliography

• Carbon Stars, by G. Wallerstein and G.R. Knapp, Ann Rev (in press 1998)
• ISO Observations of hot dust in the nucleus of the SO galaxy NGC 3998, 1996, A&A 315, L75
• The Sloan Digital Sky Survey, 1997, Sky and Telescope 94, 40
• Molecular Gas in Elliptical Galaxies: CO observations of an IRAS Flux Limited Sample, ApJ 460, 271, 1996
• The Infrared Properties of Nearby Radiop Galaxies, AJ 99, 476

• Email: gk@astro.princeton.edu