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0.7- to 23-µm photometric observations of P/Halley 1986 III and six recent bright comets
Gehrz, R. D.; Ney, E. P.
We report 0.7- to 23-µm observations of P/Halley 1986 III and six other recent bright comets. P/Halley was measured on 47 occasions between 1985 December 12 UT and 1986 May 6 UT, several times within hours of the perihelion passage on 1986 February 9 UT. Our data show that the strength of the 10-µm silicate emission feature and the tem…
Planetary Camera Observations of the M87 Stellar CUSP
Schneider, Donald P.; Lauer, Tod R.; Faber, S. M. +11 more
Analysis of V and I band HST Planetary Camera images of the giant elliptical galaxy M87 show that its central starlight distribution is consistent with the black hole M_black hole_ = 2.6 X 10^9^ M_sun_ cusp model proposed for M87 by Young et al, [ApJ, 221,721(1978)]. A combined approach of image deconvolution and modeling is used to investigate th…
Errors Associated with Fitting Gaussian Profiles to Noisy Emission-Line Spectra
Ayres, Thomas R.; Lenz, Dawn D.
Landman, Roussel-Dupre, and Tanigawa developed prescriptions to predict profile fitting errors for Gaussian emission lines perturbed by white noise. We show that their scaling laws can be generalized to more complicated signal-dependent "noise models" of common astronomical detector systems. (SECTION: Instrumentation and Data Analysis)
The spectral signature of the cooling flow in Abell 478.
Fabian, A. C.; Edge, A. C.; Johnstone, R. M. +1 more
We present X-ray spectra of Abell 478 taken with the Ginga LAC and with the Einstein SSS. The LAC data set an upper limit of ~440 M_sun_ yr^-1^ on the mass deposition rate throughout the whole cluster if a value for the galactic absorption based on 21-cm observations of H I is adopted. The SSS data strongly require an absorbing column density well…
A Multiwavelength Study of the Supernova Remnant N49 in the Large Magellanic Cloud
Blair, William P.; Raymond, John C.; Long, Knox S. +1 more
Using the 2.5 m du Pont telescope at Las Campanas, the International Ultraviolet Explorer satellite, and archival high-resolution imager X-ray data from the Einstein Observatory, we present a detailed imaging and spectroscopic study of the supernova remnant (SNR) N49 in the Large Magellanic Cloud. Although the X-ray and optical morphology of N49 a…
Spectral Synthesis in the Ultraviolet. IV. A Library of Mean Stellar Groups
O'Connell, Robert W.; Burstein, David; Wu, Chi-Chao +1 more
A library of mean UV stellar energy distributions is derived from IUE spectrophotometry of 218 stars. The spectra cover 1230-3200 A with a spectral resolution of about 6 A. They have been corrected for interstellar extinction and converted to a common flux and wavelength scale. Individual stars were combined into standard groups according to their…
Ulysses Radio and Plasma Wave Observations in the Jupiter Environment
Goetz, K.; Kellogg, P. J.; MacDowall, R. J. +23 more
The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Sim…
Planetary Camera Observations of the Central Parsec of M32
Lauer, Tod R.; Faber, S. M.; Currie, Douglas G. +8 more
Analysis of V band HST Planetary Camera images of the elliptical galaxy M32 shows that its nucleus is extremely dense and remains unresolved at even the HST diffraction limit. A combined approach of image deconvolution and model fitting is used to investigate the starlight distribution into limiting radii of 0.04" (0.14 pc at 700 kpc). The logarit…
Combined Infrared and Analytical Electron Microscope Studies of Interplanetary Dust Particles
Bradley, J. P.; Humecki, H. J.; Germani, M. S.
Ultramicrotomed thin sections (less than 100 nm thick) of eight chondritic interplanetary dust particles (IDPs) were studied by analytical electron microscopy and IR microspectroscopy with the objective of identifying IDPs or their specific components with IR spectral transmission characteristics at 10 microns similar to those of comets. Two IDPs …
Near-infrared spectroscopy of galactic Wolf-Rayet stars.
Schmutz, Werner; Howarth, Ian D.
We present high-quality near-IR spectra of 24 Galactic WR stars, of a broad range of subtypes, selected as having known distances. The data cover the region 0.97-1.12 micron and include the 10830-A He I triplet. Measurements of He I and He II lines, together with the absolute magnitudes, yield temperatures, luminosities, mass-loss rates, and termi…