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Ultraviolet Coronagraph Spectrometer Observation of the 1996 December 23 Coronal Mass Ejection
Romoli, M.; Raymond, J. C.; Ciaravella, A. +9 more
The Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO) observed a spectacular coronal mass ejection (CME) caused by a prominence eruption on 1996 December 23. The evolution of the ejected prominence material was followed for 1 hr and 50 minutes. The observation consists of a series of 5 minute exposure…
[Fe IV] in the Orion Nebula
Martin, P. G.; O'Dell, C. R.; Dufour, R. J. +6 more
Using the Goddard High-Resolution Spectrograph on the Hubble Space Telescope, we measured the flux of [Fe IV] (3d5 4P5/2 --> 3d5 6S5/2) λvac = 2836.56 Å in the Orion Nebula, the first detection of an [Fe IV] line in an H II region. A useful upper limit is set on the su…
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…
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…
Multiwavelength Monitoring of the BL Lacertae Object PKS 2155-304 in 1994 May. II. The IUE Campaign
Shull, J. Michael; Urry, C. Megan; Madejski, Greg +16 more
PKS 2155-304, the brightest BL Lac object in the ultraviolet sky, was monitored with the International Ultraviolet Explorer satellite at ~1 hr time resolution for 10 nearly uninterrupted days in 1994 May. The campaign, which was coordinated with Extreme Ultraviolet Explorer, ROSAT, and ASCA monitoring, along with optical and radio observations fro…
Observations of Doppler Shifts in a Solar Polar Coronal Hole
Wilhelm, K.; Mariska, J. T.; Warren, H. P.
Using observations from the Solar Ultraviolet Measurements of Emitted Radiation experiment flown on the Solar and Heliospheric Observatory spacecraft, we have measured Doppler wavelength shifts in the north polar coronal hole in the 1032 and 1038 Å emission lines of O VI and the 1036 and 1037 Å emission lines of C II relative to chromospheric emis…
Tomographic Separation of Composite Spectra. IV. The Physical Properties of the Massive Close Binary DH Cephei
Gies, Douglas R.; Penny, Laura R.; Bagnuolo, William G., Jr.
We present the results of a Doppler tomographic reconstruction of the UV spectra of the double-lined, O binary DH Cephei based on observations made with the International Ultraviolet Explorer. We describe cross-correlation methods we use to obtain precise radial velocities, and we present a radial velocity curve based on combined optical and UV me…
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…