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The Cassini Ion Mass Spectrometer
McComas, D. J.; Young, D. T.; Berthelier, J. -J. +2 more
The joint NASA/European Space Agency Cassini mission to Saturn will carry the Cassini Plasma Spectrometer (CAPS). This instrument consists of three sensors, including the Ion Mass Spectrometer (IMS), a data processing unit, and an actuator that rotates CAPS in order to view a large fraction of the space environment. The IMS makes high sensitivity,…
On the differential ion velocity in the inner solar corona and the observed solar wind ionic charge states
Gloeckler, George; Geiss, Johannes; Ko, Yuan-Kuen
Theoretical calculations on multifluid solar wind have indicated that the velocities of ions of the same element are not the same in the inner coronal region where the freeze-in process of these solar wind heavy ions occurs. This may have nonnegligible effect on the inference of the electron temperature in this region from the observed ionic charg…
Correlation of the HIPPARCOS and Allegheny Observatory Parallax Catalogs
Gatewood, George; Kiewiet de Jonge, Joost; Persinger, Timothy
No significant difference is found between the systems of the Hipparcos and Allegheny Observatory MAP parallax catalogs. The correlation of the parallaxes of 63 stars common to both programs is 0.9995 +/- 0.0001, with an average standard deviation of the difference of 0.0023". While there is no indication of systematic difference in the two progra…
Composition and Opacity in the Solar Interior
Turck-Chieze, Sylvaine
Detailed abundances of elements from hydrogen up to iron are necessary to perform a precise model of the solar structure. Most of them have been deduced from photospheric observed values, some others from the meteoritic composition. Nowadays, thanks to helioseismic constraints, they seem more and more under control.
Impact of the Ulysses velocity on the diagnosis of the electron density by the Unified Radio and Plasma Wave sounder in the outskirts of the Io torus
Canu, Patrick; Cornilleau-Wehrlin, Nicole; Le Sager, Philippe
The resonance spectra collected on February 8, 1992, in the outskirts of the Io plasma torus by the Unified Radio and Plasma wave (URAP) relaxation sounder on board the Ulysses spacecraft present significant differences from the active spectra gathered by earthbound spacecraft in similar plasma conditions. The most striking anomaly is the lack of …
Kinematic evidence for the wave nature of the Carina-Sagittarius arm
Dambis, A. K.; Rastorguev, A. S.; Sitnik, T. G. +2 more
Radial-velocity and (Hipparcos) proper-motion data are used to construct the residual space velocity field for OB associations in the Carina-Sagittarius arm. The azimuthal residual velocity component for most stars in the Sgr OB1, Ser OB1, Cru OB1, Cen OB1, and Car OB2 associations has the direction that is opposite to the Galactic rotation, while…
Decomposition of the rotation curves of distant field galaxies
Möllenhoff, C.; Fuchs, B.; Heidt, H.
We present decompositions of the rotation curves of distant spiral galaxies into contributions due to their bulges, disks, and putative dark haloes. In order to set constraints on the ambiguities of the decompositons we interpret the morphology of the spiral structures quantitatively in the framework of density wave theory. Galaxy models constrain…
ISO-SWS Observations of Weak Bands of Trace Components of Ices Towards the Young Stellar Object W 33A
van Dishoeck, E. F.; Whittet, D. C. B.; Schutte, W. A. +3 more
ISO-SWS observations of the highly obscured young stellar object W 33A reveal two broad absorption features centered at 7.24 and 7.40 µm. The position and width of these features indicates that they are due to the XH bending mode (X = C, N, or O) of molecules in the solid state. Comparison to interstellar ice analogs shows that the 7.24 µm band ca…
Surface Photometry of the Dwarf Elliptical Galaxies NGC 185 and NGC 205
Lee, Myung Gyoon; Kim, Sang Chul
We present BVRI CCD surface photometry for the central (6'.35 X 6'.35) regions of the dwarf elliptical galaxies NGC 185 and NGC 205 in the Local Group. Surface brightness profiles of NGC 185 (R < 225") and NGC 205 (R < 186") show excess components in the central regions. The colors of NGC 185 get bluer inward at R < 25", while they remain…
Spatially Resolved Spectra of 3C Galaxy Nuclei
Nelson, C.; Hutchings, J. B.; Kaiser, M. E. +3 more
We present and discuss visible-wavelength long-slit spectra of four low-redshift 3C galaxies obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST). The slit was aligned with near-nuclear jetlike structure seen in HST images of the galaxies, to give unprecedented spatial resolution of their inner regions. In 3C …