Search Publications
Hubble Space Telescope Observations of C 2 Molecules in Diffuse Interstellar Clouds
Federman, S. R.; Lambert, David L.; Sheffer, Yaron
Interstellar C2 F-X (1342 A) and D-X (2313 A) bands in the spectrum of zeta Oph were detected using the Goddard High-Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST). The total C2 column density is (1.79 +/- 0.06) 1013/sq cm for an adopted f-value of 0.0545 for the 2313 A band of the Mulliken (D-X) system. Relative f-v…
Cosmic Ray and Solar Particle Investigations Over the South Polar Regions of the Sun
Sierks, H.; Kunow, H.; Muller-Mellin, R. +17 more
Observations of galactic cosmic radiation and anomalous component nuclei with charged particle sensors on the Ulysses spacecraft showed that heliospheric magnetic field structure over the south solar pole does not permit substantially more direct access to the local interstellar cosmic ray spectrum than is possible in the equatorial zone. Fluxes o…
The Ultraviolet Emission Properties of 13 Quasars
Laor, Ari; Schneider, Donald P.; Green, Richard F. +2 more
We analyze the ultraviolet (UV) emission properties of a sample of 13 quasars studied with the Hubble Space Telescope (HST). The quasars redshifts are in the range 0.165 <= z <= 2.06, and their absolute magnitudes are in the range -30.1 <= M_v_ <= -24.4. The data were obtained with the Faint Object Spectrograph and have a spectral reso…
Evolution of the Symbiotic Binary System AG Draconis
Polidan, Ronald S.; Garcia, Michael R.; Mikolajewska, Joanna +2 more
We present an analysis of new and archival photometric and spectroscopic observations of the symbiotic star AG Draconis. This binary has undergone several 1 - 3 mag optical and ultraviolet eruptions during the past 15 years. Our combination of optical and ultraviolet spectroscopic data allow a more complete analysis of this system than in previous…
Discovery of Candidate Cataclysmic Variables in the Post--Core-Collapse Globular Cluster NGC 6397
Cool, Adrienne M.; Cohn, Haldan N.; Lugger, Phyllis M. +2 more
A photometric search for objects with H alpha emission in the globular cluster NGC 6397 has been carried out with the Hubble Space Telescope (HST) Planetary Camera. Images were obtained through the F675W (similar to Johnson R) and F656N (H alpha) filters, and photometry carried out on approximately 900 stars detected in the central approximately 3…
Propagation of solar oscillations through the interplanetary medium
Lanzerotti, Louis J.; Thomson, David J.; Maclennan, Carol G.
Time-series analysis of the fluxes of interplanetary charged particles measured by the Ulysses and Voyager spacecraft reveals many periodic components. From 1 to 140 µHz, the spectral components are consistent with those estimated (but not confirmed) for gravity-mode oscillations of the Sun: from 1,000 to 4,000 µHz, the spectral lines closely matc…
Hubble Space Telescope and MERLIN Observations of the Jet in 3C 273
Muxlow, T. W. B.; Davis, R. J.; Schneider, D. P. +5 more
We present red and blue images of the jet of the quasar 3C 273 obtained with the WFPC2 on the Hubble Space Telescope as well as a new radio map made with the MERLIN array. The images are of significantly better quality than those of previous data. The two maps are aligned to an accuracy of 0."020; this accuracy is achieved because both the quasar …
The Discovery of Halley-sized Kuiper Belt Objects Using the Hubble Space Telescope
Stern, S. Alan; Levison, Harold F.; Cochran, Anita L. +1 more
We report the statistical detection (at the >99% confidence level) of a population of 28th magnitude objects exhibiting proper motions of ≈1" hr-1 at quadrature in deep Hubble Space Telescope (HST)/WFPC2 images. The drift directions imply a preponderance of objects on prograde orbits concentrated near the ecliptic plane. We interpret…
Temperature inversion in the Io plasma torus.
Moncuquet, Michel; Meyer-Vernet, Nicole; Hoang, Sang
We present in situ measurements of electron parameters as a function of latitude in the Io plasma torus, deduced from an extended analysis of the radio and plasma wave data acquired on board Ulysses. We find that the density and temperature are anti-correlated and obey an approximate polytrope law Te ∝ √{1/ne}. We interpret t…
The Z = 0.8596 Damped LY alpha Absorbing Galaxy toward PKS 0454+039
Dickinson, Mark; Bowen, David V.; Steidel, Charles C. +1 more
We present Hubble Space Telescope and ground-based data on the z_abs_ = 0.8596 metal-line absorption system along the line of sight to PKS 0454+0356. The system is a moderate-redshift damped Lyα system, with N(H I) = (5.7 +/- 0.3) x 10^20^ cm^-2^ as measured from the faint Object Spectrograph spectrum. We also present ground-based images which we …