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A spectroscopic study of the surfaces of Saturn's large satellites: H ₂O ice, tholins, and minor constituents

Emery, Joshua P.; Cruikshank, Dale P.; Owen, Tobias C. +7 more

We present spectra of Saturn's icy satellites Mimas, Enceladus, Tethys, Dione, Rhea, and Hyperion, 1.0-2.5 µm, with data extending to shorter (Mimas and Enceladus) and longer (Rhea and Dione) wavelengths for certain objects. The spectral resolution ( R=λ/Δλ) of the data shown here is in the range 800-1000, depending on the specific instrumen…

The Magnetosheath

Sahraoui, F.; Lucek, E. A.; Walker, S. N. +5 more

Detection of Ne VIII in the Low-Redshift Warm-Hot Intergalactic Medium

Tripp, Todd M.; Sembach, Kenneth R.; Savage, Blair D. +2 more

High-resolution FUSE and STIS observations of the bright QSO HE 0226-4110 (z_em=0.495) reveal the presence of a multiphase absorption-line system at z_abs(OVI)=0.20701 containing absorption from H I (Lyα to Lyθ), C III, O III, O IV, O VI, N III, Ne VIII, Si III, S VI, and possibly S V. Single-component fits to the Ne VIII and O…

Weak-Lensing Analysis of the z~=0.8 Cluster CL 0152-1357 with the Advanced Camera for Surveys

Ford, H. C.; Demarco, R.; Rosati, P. +5 more

We present a weak-lensing analysis of the X-ray-luminous cluster CL 0152-1357 at z~=0.84 using Hubble Space Telescope/Advanced Camera for Surveys (ACS) observations. The unparalleled resolution and sensitivity of ACS enable us to measure weakly distorted, faint background galaxies to the extent that the number density reaches ~175 arcmin^-2

Energetic ion acceleration in Saturn's magnetotail: Substorms at Saturn?

Krupp, N.; Dougherty, M. K.; Krimigis, S. M. +11 more

The Magnetospheric Imaging Instrument (MIMI) Ion and Neutral Camera (INCA) on the Cassini spacecraft has recorded abrupt increases in energetic neutral atom flux coming from the general direction of Saturn's magnetotail. These bursts of ion activity in the tail are well correlated with enhancements in the Saturn kilometric radiation. Given the sim…

Solar wind control of the radial distance of the magnetic reconnection site in the magnetotail

Nakamura, R.; Fujimoto, M.; Baumjohann, W. +6 more

To understand magnetotail dynamics, it is essential to determine where magnetic reconnection takes place in the near-Earth magnetotail during substorms. The Geotail spacecraft thoroughly surveyed the near-Earth plasma sheet at radial distances of 10-31 R_E during the years 1995-2003. Thirty-four clear reconnection events were identified …

An XMM-Newton view of the cluster of galaxies Abell 85

Forman, W.; Durret, F.; Lima Neto, G. B.

We have observed the cluster of galaxies Abell 85 with XMM-Newton. These data have allowed us in a previous paper to confirm the existence of the extended 4 Mpc filament detected by the ROSAT PSPC in the neighbourhood of this cluster, and to determine an X-ray temperature of about ~ 2 keV. We now present a thorough analysis of the properties of th…

Characteristics of the interplanetary coronal mass ejections in the heliosphere between 0.3 and 5.4 AU

Wang, C.; Richardson, J. D.; Du, D.

We identify and characterize interplanetary coronal mass ejections (ICMEs) observed by spacecraft in the solar wind, namely Helios 1 and 2, PVO, ACE, and Ulysses, which together cover heliocentric distances from 0.3 to 5.4 AU. The primary identification signature used to look for ICMEs is abnormally low proton temperatures. About 600 probable ICME…

A Young Brown Dwarf Companion to DH Tauri

Kobayashi, Naoto; Usuda, Tomonori; Pyo, Tae-Soo +20 more

We present the detection of a young brown dwarf companion, DH Tau B, associated with the classical T Tauri star DH Tau. Near-infrared coronagraphic observations with CIAO on the Subaru Telescope have revealed DH Tau B with H=15 mag located 2.3" (330 AU) away from the primary, DH Tau A. Comparing its position with a Hubble Space Telescope archive i…

Saturn's moon Phoebe as a captured body from the outer Solar System

Lunine, Jonathan I.; Johnson, Torrence V.

The orbital properties of Phoebe, one of Saturn's irregular moons, suggest that it was captured by the ringed planet's gravitational field rather than formed in situ. Phoebe's generally dark surface shows evidence of water ice, but otherwise the surface most closely resembles that of C-type asteroids and small outer Solar System bodies such as Chi…