Star Formation in Galaxies
My research is to fully characterize the star formation properties of the local population of galaxies around the Milky Way, using four new emission-line imaging and spectrophotometric surveys of nearby galaxies. These surveys will provide the first truly complete census of star-forming galaxies in the local universe, including a sample of several hundred galaxies in 8 nearby galaxy clusters, a volume-limited survey of 385 galaxies within 11 Mpc of the Milky Way, and an NOAO survey of 500 HI-selected galaxies in the local volume. A companion survey of integrated spectra of 360 galaxies will provide improved corrections for the effects of extinction on the emission-line maps, and improved diagnostics of star formation rates and chemical abundances in galaxies. Specific projects to be carried out will include:
- A quantititative study of incompleteness in existing measurements of the volume-averaged cosmic star formation rate.
- A dissertation study of the temporal behavior of star formation and the role of starbursts in the evolution of dwarf galaxies.
- A complete characterization of the distribution of present-day star formation as functions of parent galaxy properties and surface density, and the development of metrics of these distributions that can eventually be applied to high-redshift galaxies.
- The calibration of improved diagnostics of star formation rates, dust extinction, and heavy-element abundances from integrated galaxy spectra.
- An in-depth study of the effects of aperture sampling on the interpretation of galaxy spectra.
The results of this study are important for a large number of broader problems in astrophysics including star formation, the physical nature of the Hubble sequence, and the formation and evolution of galaxies. A special effort has been made to obtain observations that complement other major surveys including the Sloan Digital Sky Survey, the Spitzer Nearby Galaxies Survey, and the many ongoing surveys of high-redshift galaxies.
--11mpc UV and H-alpha galaxy survey. This is a GALEX Legacy program
which will combine GALEX UV imaging with ground-based H-alpha and
R-band imaging for a complete sample within 11mpc local volume.
--The Spitzer Infrared Nearby Galaxies Survey is a comprehensive imaging
and spectroscopic study of 75 nearby galaxies.
--Survey for Ionization in Neutral-Gas Galaxies. The HIPASS H-alpha
survey is a project to measure ionized hydrogen in 500 galaxies.
MOSAIC cluster survey
--Used MOSAIC CCD imager on the KPNO 0.9m telescope to obtain deep obtain
deep Halpha, R, and B imaging for 8 nearby (z=.016-.024) galaxy clusters
K/M Spectra Atlas
--This is an expanded atlas of integrated spectra of 360 nearby galaxies,
covering the full range of evolutionary properties found in the local
universe, with emphasis on the actively starforming galaxies that
comprise the dominant population at higher redshifts.