The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume...
The ACS Nearby Galaxy Survey Treasury. I. The Star Formation History of the M81 Outer Disk
The Advanced Camera for Surveys (ACS) Nearby Galaxy Survey Treasury is a large Hubble Space Telescope (HST)/ACS treasury program to obtain resolved stellar...
The ACS Survey of Galactic Globular Clusters. VI. NGC 6366: A Heavily Stripped Galactic Globular Cluster
We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic globular clusters (GCs) to construct a color-magnitude diagram...
The ACS Survey of Galactic Globular Clusters. XI. The Three-dimensional Orientation of the Sagittarius Dwarf Spheroidal Galaxy and Its Globular Clusters
We use observations from the Hubble Space Telescope Advanced Camera for Surveys (HST/ACS) study of Galactic globular clusters to investigate the spatial...
The ACS Survey of Galactic Globular Clusters: M54 and Young Populations in the Sagittarius Dwarf Spheroidal Galaxy
As part of the ACS Survey of Galactic Globular Clusters, we present new Hubble Space Telescope photometry of the massive globular cluster M54 (NGC 6715) and the...
The Active Jet in NGC 4258 and Its Associated Shocks
We present images and spectra of the active jet and anomalous arms on subparsec through kiloparsec scales in the LINER/Seyfert galaxy NGC 4258 (M106). New VLBA...
The age of extremely red and massive galaxies at very high redshift
Aims: We present a determination of the intrinsic colors and ages of galaxies at very high redshift, in particular old galaxies (OGs) within extremely red...
The age-metallicity relationship in the Fornax spheroidal dwarf galaxy
We produce a comprehensive field star age-metallicity relationship (AMR) from the earliest epoch until ˜1 Gyr ago for three fields in the Fornax dwarf...
The AGN contribution to mid-infrared surveys. X-ray counterparts of the mid-IR sources in the Lockman Hole and HDF-N
We provide constraints on the AGN contribution to the mid-IR extragalactic background light from a correlation analysis of deep X-ray and mid-IR observations in...