Search Publications
Clock-like behavior of Jovian continuum radiation
Kaiser, M. L.; Desch, M. D.; Farrell, W. M.
Ulysses URAP observations of escaping Jovian continuum radiation show a persistent 10 h variation in amplitude which can best be explained by a clock like model. The continuum shows a moderately strong preference to reach maximum intensity when the 0°-90° System III longitude sector faces the Sun.
Deep Hubble Space Telescope Imaging of 53WO44: an SO Radio Galaxy at z=0.311
Keel, William C.; Windhorst, Rogier A.
We present images with the Wide-Field Camera (WFC) and Faint-Object Camera (FOC) of the radio galaxy 53W044, as part of a morphological study of the faint radio-source population. The WFC images are used to examine the structure of the galaxy, and show evidence for a significant disk (contributing 18%-20% of the light in the observed V and I bands…
Large-amplitude magnetic pulses downstream of the Jovian bow shock: Ulysses observations
Tsurutani, Bruce T.; Smith, Edward J.; Balogh, Andre +2 more
We report the first finding of large-amplitude magnetic pulses in the Jovian magnetosheath. The pulses are highly compressional with Δ| B|/| B| ranging from 0.5 to 2.0. Each pulse contains a full 360° phase rotation. These solitary waves are propagating at an angle nearly orthogonal to the ambient magnetic field ( θkB > 83°). A deter…
Further constraints on the warm absorber in MR 2251-17.8 from GINGA and EXOSAT observations.
Mineo, T.; Stewart, G. C.
Analysis of a Ginga observation of MR 2251 - 17.8 is presented. The source is in a relatively low emission state, with a high absorbing column density. This result is consistent with the previous EXOSAT observations, where a strong correlation between the flux and the column density was detected. The Ginga spectrum and the entire EXOSAT spectral d…
The highly ionised absorbing material in MR2251-178
Mineo, T.; Stewart, G. C.
Ginga observations have suggested the presence of iron absorption edges at energies appropriate for highly ionised material in the X-ray spectra of a significant number of active galactic nuclei. Here, we present a detailed self-consistent analysis of a series of Ginga and EXOSAT observations of MR2251-178, the original prototype of this warm-abso…
ULF waves in the Io torus: Ulysses observations
Forsyth, R. J.; Rezeau, L.; Lin, Naiguo +7 more
Throughout the Io torus, Ulysses has observed intense ULF wave activity in both electric and magnetic components. Such ULF waves have been previously suggested as the source of ion precipitation leading to Jovian aurorae. The peaks of the wave spectra are closely related to the ion cyclotron frequencies, which is evidence of the waves being ion cy…
Boundary layer ion composition at Jupiter during the inbound pass of the Ulysses flyby
Woch, J.; Galvin, A. B.; Mall, U. +3 more
During the inbound segment of the Ulysses flyby of Jupiter, there were multiple incursions into the dawnside low-latitude boundary layer, as identified by Bame et al. ( Science257, 1539-1542, 1992) using plasma electron data. In the present study, ion composition and spectral measurements provide independent collaborative evidence for the existenc…
Correlations between magnetic field and electron density observations during the inbound Ulysses Jupiter flyby
Dougherty, M. K.; Balogh, A.; Kellogg, P. J. +2 more
The spacecraft Ulysses flew through the Jovian magnetosphere during February 1992. This paper compares the magnetic field observations recorded during the inbound pass of the flyby with the electron density as derived from the URAP instrument. In general, it is expected that the density variations will anti-correlate with the magnetic field streng…
Faint Object Spectrograph Spectra of the UV Emission Lines in NGC 5548: Detection of Strong Narrow Components
Crenshaw, D. Michael; Wu, Chi-Chao; Boggess, Albert
Ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 were obtained with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope on 1992 July 5, when the UV continuum and broad emission lines were at their lowest ever observed level. The high resolution of the spectra, relative to previous UV observations, and the low state of NGC 5548 al…
A 4.86-h periodic modulation in the UV resonance lines of the cataclysmic variable V795 Herculis.
Prinja, Raman K.; Rosen, Simon R.
Low-resolution IUE spectroscopy of V795 Her secured in 1992 August is used to authenticate the presence of an approximately 4.86-h periodic variation in the mainly wind-formed Si IV 1400-A and C IV 1549-A resonance lines. The modulation is demonstrated to be coherent across a 3-yr time-span, and is discordant with the mooted orbital (optical spect…