15 citations · 15 across the 2 of their papers we have counts for
7 papers
Discovery of an extended halo of metal-poor stars in the Andromeda spiral galaxy
Puragra Guhathakurta, James C. Ostheimer, Karoline M. Gilbert +5
Understanding galaxy formation involves look-back and fossil-record studies of distant and nearby galaxies, respectively. Debris trails in our Galaxy's spheroidal halo of old stars…
Supernovae in Galaxy Clusters
A. Gal-Yam, D. Maoz, K. Sharon +3
We present the results of several surveys for supernovae (SNe) in galaxy clusters. SNe discovered in deep, archival HST images were used to measure the cluster SN Ia rate to z=1. A…
A Lack of Planets in 47 Tucanae from an HST Search
Ronald L. Gilliland, T. M. Brown, P. Guhathakurta +21
We report results from a large Hubble Space Telescope project to observe a significant (~34,000) ensemble of main sequence stars in the globular cluster 47 Tucanae with a goal of d…
Dwarf Spheroidal Galaxies in the M81 Group Imaged with WFPC2
I. D. Karachentsev, V. E. Karachentseva, A. E. Dolphin +7
We obtained HST/WFPC2 images of the dwarf spheroidal (dSph) galaxies K61, K63, K64, DDO78, BK6N, and kk77 in the M81 group. Our color-magnitude diagrams show red giant branches wit…
A Dwarf Galaxy Survey in the Local Volume
E. K. Grebel, P. Seitzer, A. E. Dolphin +6
We are carrying out a comprehensive multi-wavelength study of dwarf galaxies in the Local Volume (< 5 Mpc). After our all-sky survey more than doubled the dwarf census we are now m…
Breaking the Disk/Halo Degeneracy with Gravitational Lensing
Ariyeh H. Maller, Luc Simard, Puragra Guhathakurta +4
The degeneracy between the disk and the dark matter contribution to galaxy rotation curves remains an important uncertainty in our understanding of disk galaxies. Here we discuss a…