Search Publications
The Globular Cluster NGC 1978 in the Large Magellanic Cloud
Mucciarelli, Alessio; Ferraro, Francesco R.; Origlia, Livia +1 more
We have used deep, high-resolution Hubble Space Telescope ACS observations to image the cluster NGC 1978 in the Large Magellanic Cloud. This high-quality photometric data set allowed us to confirm the high ellipticity (ɛ~0.30+/-0.02) of this stellar system. The derived color-magnitude diagram allowed a detailed study of the main evolutionary seque…
A Normal Stellar Disk in the Galaxy Malin 1
Barth, Aaron J.
Since its discovery, Malin 1 has been considered the prototype and most extreme example of the class of giant low surface brightness disk galaxies. Examination of an archival Hubble Space Telescope I-band image reveals that Malin 1 contains a normal stellar disk that was not previously recognized, having a central I-band surface brightness of &mic…
Remnant of a ``Wet'' Merger: NGC 34 and Its Young Massive Clusters, Young Stellar Disk, and Strong Gaseous Outflow
Seitzer, Patrick; Schweizer, François
This paper presents new images and spectroscopic observations of NGC 34 (Mrk 938) obtained with the du Pont 2.5 m and Baade 6.5 m telescopes at Las Campanas, plus photometry of an archival V image obtained with Hubble Space Telescope. This MV=-21.6 galaxy has often been classified as a Seyfert 2, yet recently published infrared spectra …
A Catalog of Star Cluster Candidates in M33
Sarajedini, Ata; Mancone, Conor L.
We present a new catalog of star cluster candidates in the nearby spiral galaxy M33. It is based on eight existing catalogs wherein we have cross-referenced identifications and endeavored to resolve inconsistencies between them. Our catalog contains 451 candidates, of which 255 are confirmed clusters based on Hubble Space Telescope and high-resolu…
A Young Stellar Cluster Surrounding the Peculiar Eruptive Variable V838 Monocerotis
Bond, Howard E.; Afşar, Melike
V838 Monocerotis is an unusual variable star that underwent a sudden outburst in 2002. Unlike a classical nova, which quickly evolves to high temperatures, V838 Mon remained an extremely cool, luminous supergiant throughout its eruption. It continues to illuminate a spectacular series of light echoes, as the outburst light is scattered from nearby…
Dynamical Evolution of Globular Cluster Systems Formed in Galaxy Mergers: Deep Hubble Space Telescope Advanced Camera for Surveys Imaging of Old and Intermediate-Age Globular Clusters in NGC 3610
Gilmore, Diane; Whitmore, Bradley C.; Schweizer, François +1 more
The Advanced Camera for Surveys on board the Hubble Space Telescope has been used to obtain deep, high-resolution images of the giant elliptical galaxy NGC 3610, a well-established remnant of a dissipative galaxy merger. These observations supersede previous, shallower observations that revealed the presence of a population of metal-rich globular …
The Gravitational Lens-Galaxy Group Connection. II. Groups Associated with B2319+051 and B1600+434
Auger, M. W.; Fassnacht, C. D.; Lubin, L. M. +2 more
We report on the results of a spectroscopic survey of the environments of the gravitational lens systems CLASS B1600+434 (zl=0.41,zs=1.59) and CLASS B2319+051 (zl=0.62). The B1600+434 system has a time delay measured for it, and we find that the system lies in a group with a velocity dispersion of 90 km s-1
Hubble Space Telescope Photometry for the Halo Stars in the Leo Elliptical NGC 3377
Stetson, Peter B.; Layden, Andrew C.; Harris, William E. +1 more
We have used the ACS camera on HST to obtain (V,I) photometry for 57,000 red giant stars in the halo of the Leo elliptical NGC 3377, an intermediate-luminosity elliptical. We use this sample of stars to derive the metallicity distribution function (MDF) for its halo field stars and comment on its chemical evolution history compared with both large…
The Young Stellar Population of NGC 4214 as Observed with the Hubble Space Telescope. II. Results
Úbeda, Leonardo; MacKenty, John W.; Maíz-Apellániz, Jesús
We present the results of a detailed UV-optical study of the nearby dwarf starburst galaxy NGC 4214 using multifilter Hubble Space Telescope WFPC2 and STIS photometry. The stellar extinction is found to be quite patchy, with some areas having values of E(4405-5495)<0.1 mag and others, associated with star-forming regions, much more heavily obsc…
Asymmetry and Variability in the HH 30 Circumstellar Disk
Stapelfeldt, Karl R.; Watson, Alan M.
We consider optical and near-infrared images of the edge-on disk surrounding the young stellar object HH 30 taken with the Hubble Space Telescope at 18 epochs from 1994 to 2005. These images allow us to study asymmetry and variability in the disk. The lateral brightness asymmetry in the upper nebula, first seen to strongly vary in 1998, continues …