Search Publications
Time-variable magnetospheric radio emissions from Jupiter
Kaiser, M. L.
Jupiter is the source of a large number of independent nonthermal radio sources, all of which vary with time. The known causes of the variations include planetary rotation modulation, modulation by Io and/or its torus, and influence by the solar wind which can reach surprisingly deep into the Jovian magnetosphere. However, a significant number of …
Faint Object Spectrograph Spectra of the Broad Fe II Absorption Lines in the Remnant of SN 1006
Sarazin, Craig L.; Crenshaw, D. Michael; Fesen, Robert A. +2 more
Ultraviolet spectra of a hot subdwarf star located behind the remnant of SN 1006 have been obtained with the Faint Object Spectrograph on the Hubble Space Telescope. The FOS UV spectra show strong and extremely broad Fe II λ2343, λ2374, λ2382, λ2586, and λ2599 lines in absorption from the supernova remnant, confirming an earlier detection with the…
The ionization of the winds from cataclysmic variables without classical boundary layers.
Drew, Janet E.; Hoare, Melvin G.
We have calculated a grid of detailed photoionization models for the stellar winds in non-magnetic cataclysmic variables. In the light of evidence which questions the existence of a classical hot, luminous boundary layer we investigate (i) models with cool, luminous boundary layers or (ii) models with no boundary layer at all, but with a moderatel…
Ultraviolet-Excess Selection of the Counterpart to a Globular Cluster X-Ray Burster: Hubble Space Telescope Images of the Core of NGC 6712
Anderson, Scott F.; Margon, Bruce; Deutsch, Eric W. +1 more
Using the Planetary Camera on the Hubble Space Telescope, we have obtained high spatial resolution, multicolor images and photometry of the core of the globular cluster NGC 6712. A comparison of our blue and ultraviolet images unambiguously reveals a faint (B = 21), UV-excess object, 'star S', within the Einstein error box for the bursting X-ray s…
NLTE analysis of sublimous O stars : the hot subdwarf in the binary system HD 128220.
Rauch, T.
We present a precise NLTE analysis of the hot subdwarf in the double-lined spectroscopic-binary system HD128220 (BD+19°2824, SAO 101094), based on 38 high- resolution IUE spectra. Very detailed NLTE models were constructed using the Accelerated Lambda Iteration technique. Model atoms for H I, He I/He II, C III/C IV, N III/N IV and O IV/O V are car…
Chromospheric Heating by Acoustic Shocks: A Confrontation of GHRS Observations of alpha Tauri (K5 III) with AB Initio Calculations
Judge, P. G.; Cuntz, M.
We compare ab initio calculations of semiforbidden C II line profiles near 2325 A with recently published observations of the inactive red giant Alpha Tau (K5 III) obtained using the GHRS on board the Hubble Space Telescope. Our one-dimensional, time-dependent calculations assume that the chromosphere is heated by stochastic acoustic shocks genera…
Ulysses plasma observations in the Jovian magnetosheath
Thomsen, M. F.; Smith, E. J.; Bame, S. J. +2 more
The solar wind plasma experiment aboard the Ulysses spacecraft, including separate ion and electron instruments, measured the plasma properties of the Jovian magnetosheath during the February 1992 encounter with Jupiter. Seven separate magnetosheath intervals were observed, as well as four bow shock crossings and numerous encounters with the magne…
Companions to Bright S and MS Stars: Technetium Deficiency and Binarity
Johnson, Hollis R.; Ake, Thomas B.; Ameen, Mudhaffer M.
To test the popular hypothesis that technetium-deficient stars of spectral types S and MS are mass-transfer binaries, we have searched for ultraviolet light from the putative hot secondaries in spectra taken with the SWP spectrograph of IUE. Although most S and MS stars are apparently thermally pulsing AGB (asymptotic giant branch) stars whose sur…
An Improved Ultraviolet Spectral Line List for the Symbiotic Star RR Telescopii
Feibelman, W. A.; Doschek, G. A.
We have remeasured wavelengths and intensities of International Ultraviolet Explorer (IUE) spectra of the symbiotic star, RR Tel. The main work is centered on the long 820 minute exposure high-resolution spectrum obtained on 1983 June 18. The list is intended to serve as a source of improved intensities and wavelengths for the ultraviolet spectrum…
Constraints for the shape of the UV background at z=2.
Reimers, D.; Vogel, S.
Spectroscopic UV observations with the Hubble Space Telescope of the QSO HS 1700+6416 (z = 2.72) (Reimers et al. 1992,1993) offer for the first time the possibility to measure column densities of C, N and O simultaneously in several ionization stages (O III to O VI, C III and C IV, N II to N V). Photoionization models have been computed and fitted…