Search Publications
Hubble Space Telescope and Ground-based Observations of I Zw 1 and Mrk 486 and the Variability of Polarization in Radio-quiet Active Galactic Nuclei
Hines, Dean C.; Schmidt, Gary D.; Smith, Paul S. +1 more
Hubble Space Telescope UV spectropolarimetry and new ground-based optical observations of the Seyfert 1/QSO I Zw 1 and highly polarized Seyfert 1 Mrk 486 are presented. I Zw 1 is found to be a polarimetric variable. Our data show that the polarization position angle has changed by ~50° compared to measurements obtained 10-15 yr ago. There is evide…
New, sub-0.1-arcsec radio maps of two young planetary nebulae
Pedlar, A.; Bryce, M.; Thomasson, P. +2 more
Sub-0.1-arcsec maps of the 5-GHz continuum emission from two young planetary nebulae (NGC7027 and BD+303639) have been obtained by combining MERLIN and VLA observations, resulting in the highest spatial resolution radio maps of these (or any) planetary nebulae to date. Small clumps of emission are resolved within the essentially ring-like structur…
Potential Measurement of the Luminosity Function of 158 Micron [C II] at High Redshifts: A Test of Galaxy Formation Models
Stark, Antony A.
Galaxy formation scenarios predict a burst of star formation in normal galaxies at a redshift between z ~ 2 and z ~ 6 (e.g., Katz & Gunn 1991); such a starburst may be accompanied by a significant brightening of the λ = 158 µm line of C+. Galaxies that will evolve to a total luminosity L* = 5 × 1010 L
Far-Infrared Spectroscopy of Planetary Nebulae with the Kuiper Airborne Observatory
Rubin, Robert H.; Haas, Michael R.; Colgan, Sean W. J. +2 more
We present new far-infrared line observations of the planetary nebulae (PNs) NGC 7027, NGC 7009, and NGC 6210 obtained with the Kuiper Airborne Observatory (KAO). The bulk of our data are for NGC 7027 and NGC 7009, including [Ne V] 24 µm, [O IV] 26 µm, [O III] (52, 88) µm, and [N III] 57 µm. Our data for [O III] (52, 88) an…
Hubble Space Telescope Wide Field Planetary Camera 2 Imaging of the Crab Nebula. I. Observational Overview
Blair, William P.; Davidson, Kris; Henry, Richard B. C. +3 more
We present Hubble Space Telescope WFPC2 images of a portion of the Crab Nebula supernova remnant obtained using narrow passband filters. These images show a wide range of filament morphologies including small individual isolated knots, long smooth arcs, and chaotic filament complexes, with evidence that some filament cores are far denser and coole…
Hubble Space Telescope Ultraviolet Spectroscopy of Two Hot White Dwarfs
Barstow, M. A.; Holberg, J. B.; Lanz, T. +1 more
We have obtained Hubble Space Telescope high-dispersion spectroscopy of two hot white dwarfs using the Goddard High-Resolution Spectrograph. The stars were selected on the basis of EUV flux as examples of H-rich DA stars containing high and low levels of short-wavelength opacity. The high-opacity star, REJ 1614-085, possesses strong features due t…
Measurements of H I and O VI velocity distributions in the extended solar corona with UVCS/SOHO and UVCS/Spartan 201
Romoli, M.; Raymond, J. C.; Naletto, G. +23 more
The Ultraviolet Coronagraph Spectrometer on the Solar and Heliospheric Observatory, UVCS/SOHO, and the Ultraviolet Coronal Spectrometer on the Spartan 201 satellite, UVCS/Spartan, have been used to measure H I 1215.67 A˚ line profiles in polar coronal holes of the Sun at projected heliocentric heights between 1.5 and 3.0 R_solar. UVCS/SOHO also me…
Ultraviolet Photometry of Stars in the Compact Cluster R136 in the Large Magellanic Cloud
Massey, Philip; Lynds, Roger; Hunter, Deidre A. +2 more
We present ultraviolet photometry of stars in the Large Magellanic Cloud star cluster R136. The data were obtained with the refurbished Wide Field/Planetary Camera on the Hubble Space Telescope through an ultraviolet filter centered at 1750 Å (F170W). These data, combined with optical HST observations presented previously, are used to explore the …
The characteristics of the cool component of the cataclysmic binary AE Aquarii derived from its HIPPARCOS parallax
Friedjung, Michael
Observations of the parallax of the cataclysmic binary AE Aqr, using the HIPPARCOS satellite, are combined with the published spectrum and magnitudes in the K band. The radius of the cool component of the binary is probably significantly larger than that of a main sequence star of the same spectral type, though the errors and uncertainties do not …
A weak lensing survey in the fields of z~1 luminous radio sources
Smail, Ian; Bower, Richard G.
In this paper we present weak lensing observations of the fields around eight z~1 luminous radio sources. These data are used to search for the lensing signatures of mass structures that either are physically associated with the radio objects, or are foreground systems projected along the line of sight. The radio sources were all the subjects of d…