Dr. Puragra Guhathakurta
Professor of Astronomy and Astrophysics
Astronomer, UC Observatories/Lick Observatory
Office: 271 Interdisciplinary Sciences
Guhathakurta's research interests include:
- Faint blue galaxies: number versus apparent-magnitude relation,
distribution in multicolor space,shapes, and angular sizes; constraining their
redshift distribution; angular autocorrelation function; rotation speeds and
masses; tests of various galaxy-evolution models.
- Study of faint stars using multicolor CCD data: tidal debris in the
Sextans dwarf spheroidal galaxy; limits on galactic or local group baryonic
dark matter; metallicity of stars in the M31 outer spheroid.
- Search for Kuiper-belt comets; series of short CCD exposure of low
ecliptic latitude fields are filtered in order to identify objects with apparent
speeds of a few arcsed/hour.
- Gravitational lensing by galaxy clusters: systematic distortion of the
shapes of background faint blue galaxies; estimates of the mass distribution
in rich clusters at z=0.2-0.5.
- HST studies of dense globular cluster cores: density distribution near
cluster center, search for central cusps; gradients in the stellar population
versus radius; blue straggler stars.
- Near infrared Tully-Fisher diagram: secondary distance indicator;
intrinsic scatter in the relation; shapes and dust content of spiral galaxies;
kinematics of galaxy clusters; surface photometry of nearby bright spirals
and the Hubble constant.
- Galactic "cirrus" clouds: large-area CCD mosaic imaging/multicolor
surface photometry of high-latitude dust clouds; scattered starlight and
fluorescence from interstellar dust grains; grain optical properties; effect of
cirrus clouds on deep optical imaging; atomic and molecular gas content of
cirrus clouds; cloud kinematics.
- Interacting galaxies: gas content and distribution; kinematics, stellar
populations, and star formation in the merger remnant NGC 7252 (the
"Atoms-for-Peace" galaxy) and in the group of galaxies surrounding the
shell galaxy NGC 5018.
- Dwarf galaxies: an H I survey of the Perseus-Pisces super-cluster and
a foreground void; properties of 21-cm selected dwarf galaxies.