Dr. Puragra Guhathakurta

Professor of Astronomy and Astrophysics
Astronomer, UC Observatories/Lick Observatory

Office: 271 Interdisciplinary Sciences
Phone: 831-459-5169
Email: raja@ucolick.org

Research Interest:

Guhathakurta's research interests include:

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  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.
  6. 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.
  7. 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.
  8. 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.
  9. Dwarf galaxies: an H I survey of the Perseus-Pisces super-cluster and a foreground void; properties of 21-cm selected dwarf galaxies.