Search Publications
The Centers of Early-Type Galaxies with HST.I.An Observational Survey
Faber, S. M.; Dressler, A.; Byun, Y. -I. +6 more
We have obtained V-band images of 45 nearby elliptical galaxies and bulges using the original Planetary Camera of the Hubble Space Telescope. The majority of the sample is at distances of 10-20 Mpc. This represents a substantial increase in the number of galaxies that have been studied at a resolution of a few parsecs. At this resolution, many gal…
Hubble Space Telescope Observations of Young Star Clusters in NGC 4038/4039, "The Antennae" Galaxies
Whitmore, Bradley C.; Schweizer, Francois
New, high-resolution images of the disks of NGC 4038/4039 obtained with the Wide Field Camera of the Hubble Space Telescope (HST) are presented. NGC 4038/4039, nicknamed "The Antennae," is a prototypical example of a pair of colliding galaxies believed to be at an early stage of a merger. Down to the limiting magnitude of V~23 mag, the HST images …
Starbursts and Star Clusters in the Ultraviolet
Leitherer, C.; Garnett, D. R.; Heckman, T. M. +3 more
We present ultraviolet (UV) images of nine starburst galaxies obtained with the Hubble Space Telescope using the Faint Object Camera. The galaxies range in morphology from blue compact dwarfs to ultraluminous merging far-infrared galaxies. Our data combined with new and archival UV spectroscopy and far-infrared fluxes allow us to dissect the anato…
Near-coeval formation of the Galactic bulge and halo inferred from globular cluster ages
Gilmozzi, Roberto; Rich, R. Michael; Renzini, Alvio +4 more
THE morphology of our Galaxy is characterized by a disk of stars moving on circular orbits, surrounding a central spheroidal body of stars on high-velocity, randomly oriented orbits. The spheroid is further differentiated into an inner bulge and an outer halo; the bulge stars are rich in elements heavier than helium ('metals'), whereas the halo st…
Optical and Ultraviolet Analyses of ZZ Ceti Stars and Study of the Atmospheric Convective Efficiency in DA White Dwarfs
Fontaine, G.; Bergeron, P.; Wesemael, F. +3 more
New high signal-to-noise optical spectrophotometry is presented for 22 ZZ Ceti stars. The atmospheric parameters (Teff log g) and the mass are derived for each object using new model atmospheres and synthetic spectra calculated within the mixing-length theory, as well as recent published mass-radius relationships. Various parameterizati…
The Gaseous Extent of Galaxies and the Origin of Lyman-Alpha Absorption Systems: A Survey of Galaxies in the Fields of Hubble Space Telescope Spectroscopic Target QSOs
Bowen, David V.; Lanzetta, Kenneth M.; Webb, John K. +1 more
We present initial results of an imaging and spectroscopic survey of faint galaxies in fields of Hubble Space Telescope spectroscopic target QSOs. The primary objectives of the survey are (1) to determine the incidence, extent, and covering factor of extended gaseous envelopes of luminous galaxies and (2) to determine the fraction of Lyα absorptio…
Detection of an oxygen atmosphere on Jupiter's moon Europa
Feldman, P. D.; Strobel, D. F.; Weaver, H. A. +2 more
EUROPA, the second large satellite out from Jupiter, is roughly the size of Earth's Moon, but unlike the Moon, it has water ice on its surface1. There have been suggestions that an oxygen atmosphere should accumulate around such a body, through reactions which break up the water molecules and form molecular hydrogen and oxygen2,3
Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. VIII. an Intensive HST, IUE, and Ground-based Study of NGC 5548
Veilleux, S.; Shull, J. M.; Malkan, M. A. +109 more
We present the data and initial results from a combined HST/IUE/groundbased spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy …
WFPC2 Studies of the Crab Nebula. I. HST and ROSAT Imaging of the Synchrotron Nebula
Casertano, Stefano; Ballester, Gilda E.; Crisp, David +18 more
We present images of the Crab synchrotron nebula obtained with the Wide Field and Planetary Camera 2 (WFPC2) on board the Hubble Space Telescope. These data are compared with ROSAT HRI images, and with 0."5 resolution Canada-France-Hawaii Telescope (CFHT) images previously published by van den Bergh & Pritchet (1989). These data strengthen the…
Dust in the Cores of Early-Type Galaxies
Franx, M.; van Dokkum, P. G.
The dust properties of all early-type galaxies imaged with the Planetary Camera of the Hubble Space Telescope in cycles I-III are examined. Dust is detected in 31 out of 64 galaxies, although the sample is biased against the detection of dust. From the distribution of observed axis ratios of the dust features it is inferred that 78% +/- 16% of ear…