Distances and stellar populations of elliptical galaxies

We study distance determinations and stellar populations of elliptical galaxies, primarily using optical and near-IR surface brightness fluctuations (SBFs). Because SBFs of ellipticals are dominated by giant stars, near-infrared SBFs can reach much larger distances than optical SBFs but may also be more sensitive to stellar population variations among galaxies.; We begin with a discussion of the mathematics of SBF measurement. We then develop new theoretical models which are optimized for SBF predictions. With these models, we analyze the ability of SBFs to probe unresolved stellar populations. We find that optical/near-IR SBFs are much more sensitive to metallicity than to age. Therefore, SBF magnitudes and colors are a valuable tool to break the age/metallicity degeneracy.; We derive a new calibration of K-band (2.2 mum) SBFs based on high-quality observations of Fornax cluster galaxies. This new sample is more populous and covers a wider range in galaxy properties than past work. We find that K-band SBFs depend significantly on the integrated V--I galaxy color. Furthermore, the spread in the optical/IR SBFs imply that the stellar populations dominating the SBFs have a significant age range. Our findings also suggest that lower-mass cluster galaxies may have had more extended and heterogeneous star formation histories than the massive galaxies.; We use the Keck Telescope to measure K-band SBFs of NGC 4874, the dominant galaxy in the Coma cluster. We employ improved SBF analysis techniques, including the use of deep HST optical imaging to account for the contamination from faint globular clusters. Using our new calibration, we measure the distance to Coma and use this to derive the Hubble Constant.; Finally, we present a related study of high-redshift elliptical galaxies and their connection to extremely red objects (EROS). We have discovered a significant overdensity of EROS surrounding the z = 2.69 quasar QSO 1213--0017. An analysis using optical/near-IR imaging along with Keck optical spectroscopy suggests that we have discovered a coherent structure of old galaxies at z = 1.31, probably associated with a massive galaxy cluster.