Search Publications
Evolution in space and time of the quasi-static acceleration potential of inverted-V aurora and its interaction with Alfvénic boundary processes
Lucek, E.; Nilsson, H.; Karlsson, T. +8 more
Results are presented from Cluster crossings of the acceleration region of two inverted-V auroras located in the poleward part of an extensive substorm bulge. The particle and field data are used to infer the acceleration potentials of the arcs and their distribution in altitude and latitude. The C1 data are consistent with a symmetric potential p…
Suzaku and SWIFT-BAT observations of a newly discovered Compton-thick AGN
Moretti, A.; Vignali, C.; La Parola, V. +4 more
Context. Obscured AGN are fundamental to understand the history of supermassive black hole growth and their influence on galaxy formation. However, the Compton-thick AGN (NH > 1024 cm-2) population is basically unconstrained, with less than a few dozen confirmed Compton-thick AGN found and studied so far. A way …
A case study of Kelvin-Helmholtz vortices on both flanks of the Earth's magnetotail
Retinò, Alessandro; Dandouras, Iannis; Saito, Yoshifumi +8 more
Kelvin-Helmholtz instability (KHI) is a fundamental fluid dynamical process that develops in a velocity shear layer. It is excited on the tail-flanks of the Earth's magnetosphere where the flowing magnetosheath plasma and the stagnant magnetospheric plasma sit adjacent to each other. This instability is thought to induce vortical structures and pl…
Evidence for a circumnuclear and ionized absorber in the X-ray obscured broad-line radio galaxy 3C 445
Reeves, J. N.; Braito, V.; Gofford, J. +1 more
Here we present the results of a Suzaku observation of the broad-line radio galaxy 3C 445. We confirm the results obtained with the previous X-ray observations which unveiled the presence of several soft X-ray emission lines and an overall X-ray emission which strongly resembles a typical type 2 Seyfert galaxy despite of the optical classification…
Fe K Line Complex in the Nuclear Region of NGC 253
Yamasaki, Noriko Y.; Mitsuishi, Ikuyuki; Takei, Yoh
A bright, nearby edge-on starburst galaxy, NGC 253, was studied using the Suzaku, XMM, and Chandra X-ray observatories. With Suzaku and XMM we detected complex line structure of Fe K, which is resolved into three lines (Fe I at 6.4 keV, Fe XXV at 6.7 keV, and Fe XXVI at 7.0 keV) around the center of NGC 253. Especially, the Fe I and Fe XXVI lines …
Relationship between the Parameters of Coronal Holes and High-Speed Solar Wind Streams over an Activity Cycle
Obridko, V. N.; Shelting, B. D.
The comparison of the brightness and area of coronal holes (CH) to the solar wind speed, which was started by Obridko et al. (Solar Phys.260, 191, 2009a) has been continued. While the previous work was dealing with a relatively short time interval 2000 - 2006, here we have analyzed the data on coronal holes observed in the Sun throughout activity …
The initial conditions of high-mass star formation: radiative transfer models of IRDCs seen in the Herschel Hi-GAL survey
Griffin, M.; Peretto, N.; Ward-Thompson, D. +13 more
The densest infrared dark clouds (IRDCs) may represent the earliest observable stage of high-mass star formation. These clouds are very cold, hence they emit mainly at far-infrared and sub-mm wavelengths. For the first time, Herschel has provided multi-wavelength, spatially resolved observations of cores within IRDCs, which, when combined with rad…
The high-energy view of the broad-line radio galaxy 3C 111
Ballo, L.; Tombesi, F.; Reeves, J. N. +2 more
We present the analysis of Suzaku and XMM-Newton observations of the broad-line radio galaxy (BLRG) 3C 111. Its high-energy emission shows variability, a harder continuum with respect to the radio-quiet active galactic nucleus population, and weak reflection features. Suzaku found the source in a minimum flux level; a comparison with the XMM-Newto…
Gas and Dust Toward DG Tau B and VV CrA
Najita, Joan R.; Doppmann, Greg W.; Seifahrt, Andreas +3 more
We present findings for DG Tau B and VV CrA, two of the objects observed in our Spitzer Infrared Spectrograph (IRS) project to search for molecular absorption in edge-on disks, along with near-IR spectroscopy of the CO fundamental transitions and mid-IR imaging. While the only gas absorption seen in the Spitzer IRS spectrum toward DG Tau B is CO
Analytical description of physical librations of saturnian coorbital satellites Janus and Epimetheus
Robutel, Philippe; Rambaux, Nicolas; Castillo-Rogez, Julie
Janus and Epimetheus are famously known for their distinctive horseshoe-shaped orbits resulting from a 1:1 orbital resonance. Every 4 years these two satellites swap their orbits by a few tens of kilometers as a result of their close encounter. Recently Tiscareno et al. (Tiscareno, M.S., Thomas, P.C., Burns, J.A. [2009]. Icarus 204, 254-261) have …