Search Publications
Fluvial network analysis on Titan: Evidence for subsurface structures and west-to-east wind flow, southwestern Xanadu
Burr, Devon M.; Mitchell, Karl L.; Jacobsen, Robert E. +3 more
Data of Titan's surface from the Cassini-Huygens mission show inferred fluvial networks interpreted as products of liquid alkane flow. Using synthetic aperture radar (SAR) data, we delineated drainage networks, measured network parameters, and used these measurements in a simplified algorithm for classifying terrestrial drainage patterns. The resu…
Suzaku View of the Swift/BAT Active Galactic Nuclei. I. Spectral Analysis of Six Active Galactic Nuclei and Evidence for Two Types of Obscured Population
Ueda, Yoshihiro; Terashima, Yuichi; Mushotzky, Richard +2 more
We present a systematic spectral analysis with Suzaku of six active galactic nuclei (AGNs) detected in the Swift/BAT hard X-ray (15-200 keV) survey: Swift J0138.6-4001, J0255.2-0011, J0350.1-5019, J0505.7-2348, J0601.9-8636, and J1628.1-5145. This is considered to be a representative sample of new AGNs without X-ray spectral information before the…
``Geography'' of ion acceleration in the magnetotail: X-line versus current sheet effects
Zelenyi, L. M.; Grigorenko, E. E.; Hoshino, M. +2 more
Field-aligned ion beams are often observed in the Plasma Sheet Boundary Layer (PSBL) of Earth's magnetotail. We studied two types of ion beams observed in the magnetotail at different times. Both types of ion beams are pitch angle-collimated along the magnetic field direction but they differ significantly with the width of ion velocity distributio…
Benchmarking atomic data for astrophysics: Fe VII and other cool lines observed by Hinode EIS
Del Zanna, G.
The EUV spectrum of ion{Fe}{vii} is reviewed, using new rates for electron impact excitation, atomic structure calculations, and experimental data. In particular, solar observations of a sunspot loop spectrum obtained from the Hinode EUV Imaging Spectrometer (EIS) are used. Previous line identifications, mostly based on laboratory data, have been …
[O I] sub-arcsecond study of a microjet from an intermediate mass young star: RY Tauri
Dougados, C.; Cabrit, S.; Ferruit, P. +2 more
Context: High-resolution studies of microjets in T Tauri stars (cTTs) reveal key information on the jet collimation and launching mechanism, but only a handful of systems have been mapped so far.
Aims: We wish to perform a detailed study of the microjet from the 2 M⊙ young star RY Tau, to investigate the influence of its higher stel…
The Saturn hydrogen plume
Liu, X.; Shemansky, D. E.; Melin, H.
Images of the Saturn atmosphere and magnetosphere in H Lyα emission during the Cassini spacecraft pre and post Saturn orbit insertion (SOI) event obtained using the UVIS experiment FUV spectrograph have revealed definitive evidence for the escape of H I atoms from the top of the thermosphere. An image at 0.1×0.1 Saturn equatorial radii ( RS
Tools for Dissecting Supernova Remnants Observed with Chandra: Methods and Application to the Galactic Remnant W49B
Ramirez-Ruiz, E.; Jeltema, T. E.; Lopez, L. A. +1 more
We introduce methods to quantify the X-ray morphologies of supernova remnants (SNRs) observed with the Chandra X-ray Telescope. These include a power-ratio technique to measure morphological asymmetries, correlation-length analysis to probe chemical segregation and distribution, and wavelet-transform analysis to quantify the X-ray substructure. We…
Two-dimensional hybrid simulations of superdiffusion at the magnetopause driven by Kelvin-Helmholtz instability
Cowee, M. M.; Gary, S. P.; Winske, D.
This paper describes the self-consistent simulation of plasma transport across the magnetic field at the magnetopause driven by Kelvin-Helmholtz (KH) instability. Two-dimensional hybrid (kinetic ions, fluid electrons) simulations of the most KH-unstable configuration where the shear flow is oriented perpendicular to the uniform magnetic field are …
Observations and 3D MHD simulations of a solar active region jet
Gontikakis, C.; Tsinganos, K.; Archontis, V.
Aims: We study an active region jet originating from NOAA 8531 on May 15 1999. We perform 3D MHD numerical simulations of magnetic flux emergence and its subsequent reconnection with preexisting magnetic flux. Then, we compare the physical properties of the observed jet with the reconnecting outflow produced in the numerical model.
Methods: We…
Three tenuous rings/arcs for three tiny moons
Hedman, M. M.; Burns, J. A.; Cooper, N. J. +4 more
Using Cassini images, we examine the faint material along the orbits of Methone, Anthe and Pallene, three small moons that reside between the orbits of Mimas and Enceladus. A continuous ring of material covers the orbit of Pallene; it is visible at extremely high phase angles and appears to be localized vertically to within ±25 km of Pallene's inc…