Search Publications
On the Origin of the Ultraviolet Continuum in Seyfert 2 Galaxies
Colina, Luis; Pérez, Enrique; Mas-Hesse, J. Miguel +4 more
High-resolution Hubble Space Telescope ultraviolet images of the Seyfert 2 galaxies NGC 1667, NGC 3982, NGC 5427, and NGC 5953, previously known to have circumnuclear star-forming rings, are presented.
The UV images of all four Seyfert 2 galaxies show the presence of several compact UV-bright knots at distances of ~0.7-2 kpc from the nucleus …Keck Spectroscopy of Objects with Lens-like Morphologies in the Hubble Deep Field
Zepf, Stephen E.; Davis, Marc; Moustakas, Leonidas A.
We present spectroscopy from the Keck telescope of three sets of objects in the Hubble Deep Field (HDF) that have lens-like morphologies. In the case of J123641+621204, which is composed of four objects with similar colors and a mean separation of <~0.8", we find at least two distinct components at redshifts of z = 3.209 and z = 3.220 that are …
Radio Emission from Objects in the Hubble Deep Field
Fomalont, E. B.; Windhorst, R. A.; Richards, E. A. +2 more
A radio image that covers the Hubble deep field and flanking fields has been made using the VLA for 50 hr at a frequency of 8.4 GHz, a resolution of 6", and a 4.3 σ detection level of 12.2 µJy. All six radio sources detected in the deep field are identified with galaxies brighter than I = 24 mag, based on a radio/optical coincidence better t…
Hubble Space Telescope Beryllium Abundances in the α Centauri System
Pinsonneault, M. H.; Deliyannis, Constantine P.; Primas, F. +2 more
High signal-to-noise ratio Hubble Space Telescope Goddard High-Resolution Spectrograph spectra of α Centauri A (spectral type G2 V) and α Centauri B (spectral type K1 V) have been analyzed in the Be II λ3130 spectral region. Both stars offer an excellent opportunity for testing predictions of 9Be destruction since they are nearby, have …
Observations of the SW Sextantis Star BH Lyncis in a High State
Szkody, Paula; Hoard, D. W.
We present time-resolved photometry and medium resolution (2 Å) spectroscopy of the SW Sextantis star BH Lyncis obtained during a high state of the system. Previous detailed observations have been obtained only during low and intermediate states. In addition, we present the first International Ultraviolet Explorer low-resolution (6 Å) spectrum of …
HST Observations of Host Galaxies in Three Radio-selected BL Lacertae Objects
Giavalisco, Mauro; Urry, C. Megan; Scarpa, Riccardo +3 more
We present high-resolution images of three BL Lac objects (0814+425, 1823+568, 2254+074) taken with the WFPC-2 camera on Hubble Space Telescope (HST) as part of a study of BL Lacs from a complete radio-selected sample. In two cases we clearly detect the host galaxies while the third BL Lac (0814+425) is unresolved. The host galaxy of 2254+074 is a…
Do First Results from SOHO UVCS Indicate That the Solar Wind Is Accelerated by Solitary Waves?
Davila, J. M.; Ofman, L.
The Ultraviolet Coronagraph Spectrometer (UVCS) on board the recently launched US-European Solar and Heliospheric Observatory (SOHO) satellite has found O VI and H I emission lines with a broad component that corresponds to ~300 km s-1 unresolved motions at about 0.7 solar radii above the photosphere. These motions appear to be independ…
Detailed Lensing Properties of the MS 2137-2353 Core and Reconstruction of Sources from Hubble Space Telescope Imagery
Le Fèvre, O.; Hammer, F.; Luppino, G. A. +3 more
A deep HST image of the core of the cluster of galaxies MS 2137-2353 has revealed detailed morphological structures in two arc systems, which are modeled and well reproduced. An analysis of the lensing properties of the dark matter component indicates that the cluster could have a mass distribution almost as simple as a single elliptical mass dist…
The Nuclear Ionized Gas in the Radio Galaxy M84 (NGC 4374)
Heckman, Timothy M.; Bower, Gary A.; Wilson, Andrew S. +1 more
We present optical images of the nucleus of the nearby radio galaxy M84 (NGC 4374 = 3C 272.1) obtained with the Wide Field/Planetary Camera 2 aboard the Hubble Space Telescope. Our three images cover the Hα + [N II] emission lines as well as the V and I continuum bands. Analysis of these images confirms that the Hα + [N II] emission in the central…
Dust in the Small Magellanic Cloud: Interstellar Polarization and Extinction
Magalhães, A. M.; Rodrigues, C. V.; Coyne, G. V. +1 more
The typical extinction curve for the Small Magellanic Cloud (SMC), in contrast to that for the Galaxy, has no bump at 2175 Å and a steeper rise into the far-ultraviolet. For the Galaxy, the interpretation of the extinction, and therefore the dust content of the interstellar medium, has been greatly assisted by measurements of the wavelength depend…