Search Publications
Discovery of a Metal-Line Absorber Associated with a Local Dwarf Starburst Galaxy
York, Donald G.; Stocke, John T.; Keeney, Brian A. +2 more
We present optical and near-infrared images, H I 21 cm emission maps, optical spectroscopy, and Hubble Space Telescope Space Telescope Imaging Spectrograph ultraviolet spectroscopy of the QSO/galaxy pair SBS 1122+594/IC 691. The QSO sight line lies at a position angle of 27° from the minor axis of the nearby dwarf starburst galaxy IC 691 (czg…
The Hyades Binary θ2 Tauri: Confronting Evolutionary Models with Optical Interferometry
Hajian, Arsen R.; Hummel, C. A.; Johnston, K. J. +5 more
We determine the masses and magnitude difference of the components of the Hyades spectroscopic binary θ2 Tauri. We find that both components appear to be less massive and/or brighter than predicted from some recent evolutionary models. The rapid rotation and unknown rotational inclination of both components introduce uncertainty in thei…
Hubble Space Telescope Faint Object Spectrograph Spectral Mapping of V2051 Ophiuchi in a Low State
Saito, R. K.; Baptista, R.
We report a study of the spectra and structure of the accretion disk of the dwarf nova V2051 Ophiuchi while the star was in an unusual faint brightness state during 1996. The differences between the UV resonant lines and continuum disk surface brightness distributions indicate a vertically extended disk with the emission from these lines arising f…
The Correlation Dimension of Young Stars in Dwarf Galaxies
Odekon, Mary Crone
We present the correlation dimension of resolved young stars in four actively star-forming dwarf galaxies that are sufficiently resolved and transparent to be modeled as projections of three-dimensional point distributions. We use data from the Hubble Space Telescope archive; photometry for one of the galaxies, UGCA 292, is presented here for the …
UBVI CCD Photometry of the Old Open Cluster Berkeley 17
Chaboyer, Brian; Krusberg, Zosia A. C.
Photometric UBVI CCD photometry is presented for NGC 188 and Berkeley 17. Color-magnitude diagrams (CMDs) are constructed and reach well past the main-sequence turnoff for both clusters. Cluster ages are determined by means of isochrone fitting to the cluster CMDs. These fits are constrained to agree with spectroscopic metallicity and reddening es…
A Far-Ultraviolet Study of the Hot White Dwarf in the Dwarf Nova WW Ceti
Szkody, Paula; Sion, Edward M.; Godon, Patrick +1 more
We present a synthetic spectral analysis of IUE archival and FUSE (Far Ultraviolet Spectroscopic Explorer) far-UV spectra of the peculiar dwarf nova WW Cet. During the quiescence of WW Cet, a white dwarf with Twd~26,000+/-1000 K can account for the far-UV flux and yields the proper distance. However, the best agreement with the observat…
Predictions and Strategies for Integral-Field Spectroscopy of High-Redshift Galaxies
Erb, Dawn K.; Steidel, Charles C.; Law, David R.
We investigate the ability of infrared integral-field spectrographs to map the velocity fields of high-redshift galaxies, presenting a formalism that can be applied to any telescope and imaging spectrograph system. We discuss the 5 σ limiting line fluxes that current integral-field spectrographs reach and extend this discussion to consider future …
The Deepest Supernova Search is Realized in the Hubble Ultra Deep Field Survey
Riess, Adam G.; Strolger, Louis-Gregory
The Hubble Ultra Deep Field Survey has provided the deepest optical and near-infrared views of the universe yet, and has enabled a search for the most distant supernovae, to z~2.2. We have found four supernovae by searching spans of integrations of the Ultra Deep Field and the Ultra Deep Field Parallels taken with the Hubble Space Telescope paired…
WLM-1: An old, Nonrotating, Gravitationally Unperturbed, Highly Elliptical Extragalactic Globular Cluster
Stephens, Andrew W.; Catelan, Márcio; Contreras, Roxana P.
Globular clusters have long been known for presenting (at times) significant deviations from spherical symmetry. While rotation has been the main proposed explanation, other complicating factors such as their constant interaction with the strong gravitational potential of their host galaxy have made it difficult for a consensus to be reached. To a…
The Recent Star Formation in NGC 6822 from Hubble Space Telescope Imaging
Bianchi, Luciana; Efremova, Boryana V.
We present Hubble Space Telescope WFPC2 and STIS imaging of the low-metallicity galaxy NGC 6822, performed as part of a study of the young stellar populations in the galaxies of the Local Group. Eleven WFPC2 pointings, with some overlap, cover two regions extending over 19 and 13 arcmin2, respectively, off the galaxy center. The filters…