Search Publications
Background Subtraction for the SECCHI/COR1 Telescope Aboard STEREO
St. Cyr, O. C.; Burkepile, J. T.; Thompson, W. T. +2 more
COR1 is an internally occulted Lyot coronagraph, part of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite aboard the twin Solar Terrestrial Relations Observatory (STEREO) spacecraft. Because the front objective lens is subjected to a full solar flux, the images are dominated by instrumental scattered light …
Iapetus: Unique Surface Properties and a Global Color Dichotomy from Cassini Imaging
West, Robert A.; Porco, Carolyn C.; Burns, Joseph A. +8 more
Since 2004, Saturn’s moon Iapetus has been observed repeatedly with the Imaging Science Subsystem of the Cassini spacecraft. The images show numerous impact craters down to the resolution limit of ~10 meters per pixel. Small, bright craters within the dark hemisphere indicate a dark blanket thickness on the order of meters or less. Dark, equator-f…
On the Analysis of the Complex Forbush Decreases of January 2005
Malandraki, O.; Mavromichalaki, H.; Papaioannou, A. +5 more
In this work an analysis of a series of complex cosmic ray events that occurred between 17 January 2005 and 23 January 2005 using solar, interplanetary and ground based cosmic ray data is being performed. The investigated period was characterized both by significant galactic cosmic ray (GCR) and solar cosmic ray (SCR) variations with highlighted c…
Galaxy Clusters in the Swift/BAT Era. II. 10 More Clusters Detected Above 15 keV
Böhringer, H.; Cusumano, G.; Cappelluti, N. +4 more
We report on the discovery of 10 additional galaxy clusters detected in the ongoing Swift/Burst Alert Telescope (BAT) all-sky survey. Among the newly BAT-discovered clusters there are Bullet, A85, Norma, and PKS 0745-19. Norma is the only cluster, among those presented here, which is resolved by BAT. For all the clusters, we perform a detailed spe…
Time development of field-aligned currents, potential drops, and plasma associated with an auroral poleward boundary intensification
Goldstein, M. L.; McFadden, J. P.; Mozer, F. S. +5 more
We present a detailed case study of the plasma and fields measured by the Cluster spacecraft fleet at the high-altitude auroral zone (∼3.5 RE) across the plasma sheet boundary layer and into the polar cap. This event, which occurred during quiet geomagnetic conditions (Kp = 1+, AE = 50 nT), is of particular interest in that C…
Statistical comparison of the observed and synthetic hydrogen Lyman line profiles in solar prominences
Heinzel, P.; Anzer, U.; Schmieder, B. +2 more
Aims: We analyse a unique set of prominence SOHO/SUMER Lyman spectra by comparing it with synthetic spectra obtained by 2D multi-thread prominence fine-structure models.
Methods: We employed a novel statistical approach to the analysis of the observed and synthetic Lyman spectra. We compared the statistical distributions of the line prop…
Densities and temperatures in the Venus mesosphere and lower thermosphere retrieved from SOIR on board Venus Express: Retrieval technique
Vandaele, A. C.; Robert, S.; Wilquet, V. +5 more
The SOIR instrument, flying on board Venus Express, operates in the infrared spectral domain and uses the solar occultation technique to determine the vertical profiles of several key constituents of the Venus atmosphere. The retrieval algorithm is based on the optimal estimation method, and solves the problem simultaneously on all spectra belongi…
Magnetic reconnection and cold plasma at the magnetopause
Laitinen, T.; Nilsson, H.; André, M. +5 more
We report on detailed observations by the four Cluster spacecraft of magnetic reconnection and a Flux Transfer Event (FTE) at the magnetopause. We detect cold (eV) plasma at the magnetopause with two independent methods. We show that the cold ions can be essential for the electric field normal to the current sheet in the separatrix region at the e…
Earthward electric field in the magnetotail: Cluster observations and theoretical estimates
Petrukovich, A. A.; Zelenyi, L. M.; Artemyev, A. V.
In this paper we present an experimental evidence of the existence of the earthward electric field in the thin current sheet of the Earth magnetotail. This field plays an essential role in the redistribution of observed intensities of cross-tail proton and electron currents. We consider the statistics of 59 thin current sheet crossings observed by…
The Axis Ratio Distribution of X-ray Clusters Observed by XMM-Newton
Kawahara, Hajime
We derive the axis ratio distribution of X-ray clusters using the XMM-Newton catalog. By fitting the contour lines of the X-ray image by ellipses, we confirm that the X-ray distribution is well approximated by the elliptic distribution with a constant axis ratio and direction. We construct a simple model describing the axis ratio of the X-ray gas …