Search Publications
Statistical Analysis of Reconnection Inflows in Solar Flares Observed with SOHO EIT
Shibata, Kazunari; Narukage, Noriyuki
We report observations of reconnection inflows in extreme ultraviolet (EUV) Fe XII λ195 images with the Extreme Ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO). Yokoyama and colleagues reported the first example observed on 1999 March 18. We survey the EIT data from 1996 to 2000 and find six new inflow ev…
Wake formation behind positively charged spacecraft in flowing tenuous plasmas
Eriksson, A. I.; Engwall, E.; Forest, J.
Spacecraft in tenuous plasmas become positively charged because of photoelectron emission. If the plasma is supersonically drifting with respect to the spacecraft, a wake forms behind it. When the kinetic energy of the positive ions in the plasma is not sufficient to overcome the electrostatic barrier of the spacecraft potential, they scatter on t…
Saturn lightning recorded by Cassini/RPWS in 2004
Gurnett, D. A.; Kurth, W. S.; Rucker, H. O. +8 more
During 2004 the Cassini/RPWS (Radio and Plasma Wave Science) instrument recorded about 5400 SEDs (Saturn Electrostatic Discharges), which were organized in 4 storm systems and 95 episodes. A computer algorithm with different intensity thresholds was applied to extract the SEDs from the RPWS data, and a statistical analysis on the main characterist…
Binary and Multiple O-Type Stars in the Cassiopeia OB6 Association
Gies, Douglas R.; Bagnuolo, William G., Jr.; McSwain, M. Virginia +3 more
We present the results of time-resolved spectroscopy of 13 O-type stars in the Cas OB6 stellar association. We conducted a survey for radial velocity variability in search of binary systems, which are expected to be plentiful in young OB associations. Here we report the discovery of two new single-lined binaries, and we present new orbital element…
Observations of Vertical Reflections from the Topside Martian Ionosphere
Gurnett, D. A.; Morgan, D. D.; Orosei, R. +7 more
The Martian ionosphere has for the first time been probed by a low frequency topside radio wave sounder experiment (MARSIS) (Gurnett et al., 2005). The density profiles in the Martian ionosphere have for the first time been observed for solar zenith angles less than 48 degrees. The sounder spectrograms typically have a single trace of echoes, whic…
SPICAM IR acousto-optic spectrometer experiment on Mars Express
Gondet, B.; Grigoriev, A.; Bertaux, Jean-Loup +14 more
The SPICAM IR spectrometer on Mars Express mission (1.0-1.7 µm, spectral resolution 0.5-1.2 nm) is dedicated primarily to nadir measurements of H2O abundance. It is one of two channels of SPICAM UV-IR instrument. In this spectrometer we applied for the first time in planetary research the technology of an acousto-optic tunable fil…
High-redshift Faranoff-Riley type II radio galaxies: X-ray properties of the cores
Hardcastle, M. J.; Worrall, D. M.; Belsole, E.
We present an extensive X-ray spectral analysis of the cores of 19 Faranoff-Riley type II sources in the redshift range 0.5 < z < 1.0 which were selected to be matched in isotropic radio power. The sample consists of 10 radio galaxies (RGs) and nine quasars. We compare our results with the expectations from a unification model that ascribes …
Type II Quasars from the Sloan Digital Sky Survey. IV. Chandra and XMM-Newton Observations Reveal Heavily Absorbed Sources
Strauss, Michael A.; Schneider, Donald P.; Heckman, Timothy M. +4 more
We are carrying out sensitive X-ray observations with Chandra and XMM-Newton of type II quasars selected from the Sloan Digital Sky Survey based on their optical emission line properties. In this paper we present the first results of our program. We present observations of four objects at redshifts 0.4<z<0.8, and an analysis of the archival …
Enceladus' Varying Imprint on the Magnetosphere of Saturn
Krupp, N.; Woch, J.; Dougherty, M. K. +6 more
The bombardment of Saturn's moon Enceladus by >20-kiloelectron volt magnetospheric particles causes particle flux depletions in regions magnetically connected to its orbit. Irrespective of magnetospheric activity, proton depletions are persistent, whereas electron depletions are quickly erased by magnetospheric processes. Observations of these …
Ultraviolet-to-far infrared properties of Lyman break galaxies and luminous infrared galaxies at z ~ 1
Ilbert, O.; Buat, V.; Burgarella, D. +13 more
Aims.We present the first large, unbiased sample of Lyman Break Galaxies (LBGs) at z ∼ 1. Far ultraviolet-dropout (1530 Å) galaxies in the Chandra Deep Field South have been selected using GALEX data. This first large sample in the z ∼ 1 universe provides us with a high quality reference sample of LBGs.
Methods: .We analyzed the sample from t…