Search Publications
Missions
Journals
Publication Years
Resolution and Kinematics of Molecular Gas Surrounding the Cloverleaf Quasar at Z = 2.6 Using the Gravitational Lens
Yun, M. S.; Blandford, R. D.; Scoville, N. Z. +1 more
Gravitational lenses have long been advertised as primitive telescopes, capable of magnifying cosmologically distant sources. In this Letter we present new, 0.9" resolution CO (7-6) observations of the z = 2.56 Cloverleaf quasar (H1413+117) and spatially resolved images. By modeling the gravitational lens, we infer a size scale of 0.3" (~1 kpc) fo…
Improved Evidence for a Black Hole in M32 from HST/FOS Spectra. I. Observations
van der Marel, Roeland P.; Rix, Hans-Walter; de Zeeuw, P. Tim
We have obtained spectra through small apertures centered on the nuclear region and major axis of M32 with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST). A detailed analysis and reduction of the data is presented, including (1) new calibrations and modeling of the FOS aperture sizes, point-spread function, and line-spread…
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…
Modeling the distribution of magnetic fluxes in field concentrations in a solar active region
Shine, Richard A.; Title, Alan M.; Schrijver, Carolus J. +1 more
Much of the magnetic field in solar and stellar photospheres is arranged into clusters of `flux tubes', i.e., clustered into compact areas in which the intrinsic field strength is approximately a kilogauss. The flux concentrations are constantly evolving as they merge with or annihilate against other concentrations, or fragment into smaller concen…
Observations of the Hubble Deep Field with the Infrared Space Observatory - II. Source detection and photometry
Elbaz, D.; Danese, L.; Franceschini, A. +18 more
We present positions and fluxes of point sources found in the Infrared Space Observatory (ISO) images of the Hubble Deep Field (HDF) at 6.7 and 15 mu. We have constructed algorithmically selected `complete' flux-limited samples of 19 sources in the 15-mu image, and seven sources in the 6.7-mu image. The typical flux limit at 15 mu is ~0.2 mJy and …
Rings and Satellites of Uranus: Colorful and Not So Dark
Karkoschka, Erich
Photometric properties of nine uranian satellites and four rings, based on six Hubble Space Telescope images taken in 1995, are presented. Derived albedos are consistent with previous data taken at the same phase angle of 1°, but inconsistent with most Voyager-based estimates extrapolated from observations at phase angles above 15°. The shape of p…
The Digital Wave-Processing Experiment on Cluster
Woolliscroft, L. J. C.; Alleyne, H. St. C.; Dunford, C. M. +7 more
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 …