Search Publications
Forward and reverse CIR shocks at 4-5 AU: Ulysses
Tsurutani, B. T.; Echer, E.; Guarnieri, F. L.
In this article, we study fast shocks at CIR boundaries during an extended interval of 15 consecutive major high speed solar wind streams in 1992-1993. Ulysses was 4-5 AU from the sun. The Abraham-Schrauner shock normal method and the Rankine-Hugoniot relations were used to determine fast shock directions and speeds. Out of 33 potential CIR shocks…
Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole
Genzel, R.; Pantin, E.; Grosso, N. +11 more
Sagittarius A★(SgrA★) is the supermassive black hole residing at the center of the Milky Way. It has been the main target of an extensive multiwavelength campaign we carried out in April 2007. Herein, we report the detection of a bright flare from the vicinity of the horizon, observed simultaneously in X-rays (XMM-Newton/EPIC…
Study of the solar Slow Sonic, Alfvén and Fast Magnetosonic transition surfaces
Katsikas, Valadis; Exarhos, George; Moussas, Xenophon
In this paper we study the shape, extend and time variations of the solar wind transition surfaces using the Lima and Priest (1993) hydrodynamic model adequately adapted for the case of the solar wind flow. The transition surfaces, namely the Slow (Sonic), the Alfvén, and the Fast Magnetosonic surface, are important boundaries around the Sun and p…
Infrared studies of molecular shocks in the supernova remnant HB 21: II. Thermal admixture of shocked H2 gas in the south
Koo, Bon-Chul; Lee, Ho-Gyu; Moon, Dae-Sik +2 more
We present near- and mid-infrared observations on the shock-cloud interaction region in the southern part of the supernova remnant HB 21, performed with the InfraRed Camera (IRC) aboard AKARI satellite and the Wide InfraRed Camera (WIRC) at the Palomar 5 m telescope. The IRC 4 µm (N4), 7 µm (S7), and 11 µm (S11) band images and t…
Computer modelling of a penetrator thermal sensor
Kargl, G.; Hagermann, A.; Green, S. F. +5 more
The Philae lander is part of the Rosetta mission to investigate comet 67P/Churyumov-Gerasimenko. It will use a harpoon like device to anchor itself onto the surface. The anchor will perhaps reach depths of 1-2 m. In the anchor is a temperature sensor that will measure the boundary temperature as part of the MUPUS experiment. As the anchor attains …
A morphological study of CMEs using wavelet analysis
Raga, A. C.; Blanco-Cano, X.; González-Gómez, D. I.
The principal objective of this study is to analyze structures of Coronal Mass Ejections (CMEs) using a wavelet technique. We use data measured with the SOHO/LASCO coronographs C2-C3, EIT and STEREO COR1A-B, COR2A-B. We have found that different structures show up in a CME at different spatial scales of wavelets. We also study the orientation of t…
Theoretical properties of offset bipolar electric field solitary structures in space plasmas
Torkar, Klaus; Liu, Zhenxing; Shi, Jiankui +1 more
The bipolar electric field solitary (EFS) structures have been frequently observed in the near Earth plasma regions, such as auroral zone, magnetopause, cusp regions, and magneto-tail. Sometimes these structures are observed as offset bipolar structures. In this paper, the properties of the offset bipolar EFS structures parallel to the magnetic fi…
On the nature of coronal loops above the quiet sun network
Peter, H.; Zacharias, P.; Bingert, S. +1 more
The structure and dynamics of a box in a stellar corona can be modeled employing a 3D MHD model for different levels of magnetic activity. Depending on the magnetic flux through the surface the nature of the resulting coronal structures can be quite different. We investigate a model of an active region for two sunspots surrounded by magnetic field…
On high-altitude electric fields in the auroral downward current region and their coupling to ionospheric electric fields
Marklund, G. T.
The downward field-aligned current region plays an active role in magnetosphere-ionosphere coupling processes associated with aurora. A quasi-static electric field structure with a downward parallel electric field forms at altitudes between 800 km and 5000 km, accelerating ionospheric electrons upward, away from the auroral ionosphere. Other pheno…