Search Publications
The Acs Survey of Globular Clusters. V. Generating a Comprehensive Star Catalog for each Cluster
Milone, Antonino P.; Anderson, Jay; Majewski, Steven R. +10 more
The ACS Survey of Globular Clusters has used Hubble Space Telescope's Wide-Field Channel to obtain uniform imaging of 65 of the nearest globular clusters to provide an extensive homogeneous data set for a broad range of scientific investigations. The survey goals required not only a uniform observing strategy, but also a uniform reduction strategy…
The Structure of Classical Bulges and Pseudobulges: the Link Between Pseudobulges and SÉRSIC Index
Drory, Niv; Fisher, David B.
In this paper, we study the properties of pseudobulges (bulges that appear similar to disk galaxies) and classical bulges (bulges which appear similar to E-type galaxies) in bulge-disk decompositions. We show that the distribution of bulge Sérsic indices, nb , is bimodal, and this bimodality correlates with the morphology of the bulge. …
Meeting the Cool Neighbors. X. Ultracool Dwarfs from the 2MASS All-Sky Data Release
Kirkpatrick, J. Davy; Reid, I. Neill; Lowrance, Patrick +5 more
Using data from the 2 Micron All Sky Survey All-Sky Point Source Catalogue, we have extended our census of nearby ultracool dwarfs to cover the full celestial sphere above Galactic latitude of 15°. Starting with an initial catalog of 2,139,484 sources, we have winnowed the sample to 467 candidate late-type M or L dwarfs within 20 pc of the Sun. Fi…
The Nucleus of the Sagittarius Dsph Galaxy and M54: a Window on the Process of Galaxy Nucleation
Dalessandro, E.; Bellazzini, M.; Monaco, L. +6 more
We present the results of a thorough study of the nucleus of the Sgr dwarf spheroidal galaxy (Sgr dSph) and of the bright globular cluster M54 (NGC 6715) that resides within the same nucleus (Sgr,N). We have obtained accurate radial velocities and metallicity estimates for 1152 candidate red giant branch stars of Sgr and M54 lying within ~9' from …
Age Determination of Six Intermediate-Age Small Magellanic Cloud Star Clusters with HST/ACS
Grebel, Eva K.; Gallagher, John S., III; Sabbi, Elena +9 more
We present a photometric analysis of the star clusters Lindsay 1, Kron 3, NGC 339, NGC 416, Lindsay 38, and NGC 419 in the Small Magellanic Cloud (SMC), observed with the Hubble Space Telescope Advanced Camera for Surveys (ACS) in the F555W and F814W filters. Our color-magnitude diagrams (CMDs) extend ~3.5 mag deeper than the main-sequence turnoff…
Proper Motions of the Large Magellanic Cloud and Small Magellanic Cloud: Re-Analysis of Hubble Space Telescope Data
Piatek, Slawomir; Pryor, Carlton; Olszewski, Edward W.
Kallivayalil et al. have used the Hubble Space Telescope to measure proper motions of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) using images in 21 and five fields, respectively, all centered on known quasi-stellar objects (QSOs). These results are more precise than previous measurements, but have surprising and important ph…
Dynamical Centers and Noncircular Motions in THINGS Galaxies: Implications for Dark Matter Halos
Walter, F.; Brinks, E.; de Blok, W. J. G. +2 more
We present harmonic decompositions of the velocity fields of 19 galaxies from The H I Nearby Galaxy Survey (THINGS) which quantify the magnitude of the noncircular motions in these galaxies and yield observational estimates of the elongations of the dark matter halo potentials. Additionally, we present accurate dynamical center positions for these…
Halo Gas Cross Sections and Covering Fractions of Mg II Absorption Selected Galaxies
Kacprzak, Glenn G.; Steidel, Charles C.; Churchill, Christopher W. +1 more
We examine halo gas cross sections and covering fractions, fc , of intermediate-redshift Mg II absorption selected galaxies. We computed statistical absorber halo radii, Rx, using current values of dN/dz and Schechter luminosity function parameters, and have compared these values to the distribution of impact parameters and l…
A New Distance to the Antennae Galaxies (NGC 4038/39) Based on the Type Ia Supernova 2007sr
Schweizer, François; Madore, Barry F.; Freedman, Wendy L. +13 more
Traditionally, the distance to NGC 4038/39 has been derived from the systemic recession velocity, yielding about 20 Mpc for H 0 = 72 km s-1 Mpc-1. Recently, this widely adopted distance has been challenged based on photometry of the presumed tip of the red giant branch (TRGB), which seems to yield a shorter distanc…
a SUBARU Archival Search for Faint Trans-Neptunian Objects
Fuentes, Cesar I.; Holman, Matthew J.
We present the results of a survey for trans-Neptunian objects (TNOs) based on Subaru archival images, originally collected by Sheppard et al. in 2005 as part of a search for irregular satellites of Uranus. The survey region covers 2.8 deg2, centered on Uranus and observed near opposition on two adjacent nights. Our survey reaches half …