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The gravitational lensing nature of the Cloverleaf unveiled in CO (7-6) line emission.
Antonucci, R.; Tacconi, L.; Alloin, D. +2 more
We report 0.5" resolution imaging of the Cloverleaf quasar in the CO(7-6) line and 1.3mm continuum,, as well as 1" resolution imaging in the CO(3-2) line, performed with the IRAM interferometer. The CO(7-6) image is clearly resolved into 4 spots, demonstrating that the CO emission is also gravitationally lensed. We do not find any convincing evide…
Influence of heavy ions on the high-speed solar wind
Li, Xing; Habbal, Shadia R.; Esser, Ruth +1 more
We present the results of a parameter study of the influence of heavy ions on the background solar wind, choosing doubly ionized helium, or alpha particles, and O+6, as examples. Using a three-fluid solar wind model, we keep the input parameters to the electrons and protons unchanged and investigate the effects of changing the input ene…
Absolute Flux Distributions of Solar Analogs from the UV to the Near-IR
Colina, Luis; Bohlin, Ralph
The 0.225-2.695mu m absolute flux distributions of the solar analogs P041C, P177D, and P330E are presented. The ultraviolet and optical wavelength range from 0.225mu m to 0.825mu m is based on high signal-to-noise spectra obtained with the HST Faint Object Spectrograph (FOS). The spectra in the near-infrared longward of 0.825mu m are scaled versio…
Diffusive Shock Acceleration in Oblique Magnetohydrodynamic Shocks: Comparison with Monte Carlo Methods and Observations
Jones, T. W.; Kang, Hyesung
We report simulations of diffusive particle acceleration in oblique magnetohydrodynamical (MHD) shocks. These calculations are based on extension to oblique shocks of a numerical model for ``thermal leakage'' injection of particles at low energy into the cosmic-ray population. That technique, incorporated into a fully dynamical diffusion-convectio…
Nuclear Properties of Kinematically Distinct Cores
Rich, R. Michael; Carollo, C. Marcella; Danziger, I. John +1 more
We present WFPC2 F450W, F555W, and F814W photometry for three early-type galaxies with kinematically distinct cores (KDCs), namely NGC 2434, NGC 7192, and IC 4889. For these three objects we present the B, V, and I nuclear surface brightness, isophotal, B-V and V-I profiles and derive the deprojected luminosity densities. The three KDCs have nucle…
Is there really a supermassive black hole in M87?
Marconi, A.; Macchetto, F. D.; Capetti, A. +3 more
We present the first HST long-slit spectrum of a gaseous disc around a candidate supermassive black hole. The results of this study on the kinematics of the gaseous disc in M87 are a considerable improvement in both spatial resolution and accuracy over previous observations, and require a projected mass of MBH(sin i)2 = (2.0±…
Variations of the stellar wind in early-B hypergiants.
Stahl, O.; Wolf, B.; Lamers, H. J. G. L. M. +9 more
With our fiber-linked echelle spectrograph we monitored three early-B hypergiants with high dispersion and good coverage in time. The program stars ζ^1^ Sco (HD 152236), HD 169454, and HD 190603 were observed over periods of several months in several seasons. In the years 1990 to 1994, we covered the wavelength range from 4000Å to 6740Å and in 199…
1995 observations of Martian dust storms using the Hubble Space Telescope
Bell, James F., III; Wolff, Michael J.; Clancy, R. Todd +3 more
A synoptic monitoring program of Mars using the Wide Field Planetary Camera 2 on board the Hubble Space Telescope has resulted in the observation of discrete dust activity for two dates following the 1995 opposition. Data obtained on April 8 (LS=82°) and August 21, 1995 (LS=145°) reveal the presence of local dust storms in th…
The Orbit of Charon
Buie, Marc W.; Tholen, David J.
The orbit of Charon has been determined from 60 images of the Pluto-Charon system acquired with the Hubble Space Telescope Wide Field and Planetary Camera between 1992 May 21 and 1993 August 18. The semimajor axis was found to be 19,636 ± 8 km, in good agreement with an older determination upon which mutual-event-based radius computations have rel…
Isotopic Abundances of Fe and Ni in Galactic Cosmic-Ray Sources
Simpson, J. A.; Connell, J. J.
With a new instrument, designed to determine the isotopic composition of Galactic cosmic-ray nuclei, on board the Ulysses spacecraft, we report relative abundance measurements for 54Fe, 55Fe, 56Fe, 57Fe, 58Fe and 58Ni, 59Ni, 60Ni, 62Ni in the overall…