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Occurrence and location of concentrated load and generator regions observed by Cluster in the plasma sheet
Dandouras, I.; Hamrin, M.; Norqvist, P. +4 more
Here, and in a companion paper by Hamrin et al. (2009) [Scale size and life time of energy conversion regions observed by Cluster in the plasma sheet], we investigate localized energy conversion regions (ECRs) in the Earth's plasma sheet. In total we have studied 151 ECRs within 660 h of plasma sheet data from the summer and fall of 2001 when Clus…
Wave emissions at half electron gyroharmonics in the equatorial plasmasphere region: CLUSTER observations and statistics
Canu, P.; Darrouzet, F.; Suraud, X. +5 more
Stellar content of the interacting galaxies of the M51 system
Tikhonov, N. A.; Galazutdinova, O. A.; Tikhonov, E. N.
Based on archival Hubble Space Telescope ACS/WFC images, we have performed stellar photometry for more than 0.6 million stars in the interacting galaxies NGC 5194 and NGC 5195 of the M51 system. Stars of various ages have been identified on the constructed Hertzsprung-Russell diagram: blue and red supergiants, AGB stars, and red giants. The distan…
Tangential Motions and Spectroscopy Within NGC 6720, the Ring Nebula
O'Dell, C. R.; Henney, W. J.; Sabbadin, F.
We have combined recent Hubble Space Telescope/WFPC2 images in the [O III] 5007 Å and [N II] 6583 Å lines with similar images made 9.557 years earlier to determine the motion of the Ring Nebula within the plane of the sky. Scaled ratio images argue for homologous expansion, that is, larger velocities scale with increasing distance from the central…
Probing the internal structure of the nuclei of comets
Lasue, J.; Levasseur-Regourd, A. C.; Hadamcik, E. +1 more
There is no direct evidence about the internal structure of cometary nuclei, which are mostly hidden by their gas and dust comae, and have not yet been orbited by any spacecraft. Their densities are low, typically of about 400 kg m -3 for 9P/Tempel 1 (that was impacted by the Deep Impact probe) and 67P/Churyumov-Gerasimenko (that is the…
A Low-Redshift Galaxy Cluster X-Ray Temperature Function Incorporating Suzaku Data
Shang, Cien; Scharf, Caleb
We present the first results of a survey of 14 low-redshift galaxy clusters using Suzaku. Although luminous (Lx > 1 × 1043 erg s-1 (0.1-2.4 keV)), these clusters have no prior pointed X-ray data. Together with 47 other systems they form a flux-limited sample (fx > 1.0 × 10-11 erg s-…
Solar wind erosion of the polar regions of the Mars ionosphere
Lundin, R.; Pérez-de-Tejada, H.; Reyes-Ruiz, M. +1 more
Measurements conducted with the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) instrument of the Mars Express spacecraft provide data of plasma fluxes that stream away from the polar regions of the Mars ionosphere with energy spectra whose peak value increases with distance from the planetary surface. The observed energy distribution rev…
Sources of Solar Total Irradiance Variations
Withbroe, George L.
The daily images and magnetograms acquired by MDI are a rich source of information about the contributions of different types of solar regions to variations in the total solar irradiance (TSI). These data have been used to determine the temporal variation of the MDI irradiance, the mean intensity of the solar disk in the continuum at 676.8 nm. The…
Solar stereoscopy - where are we and what developments do we require to progress?
Feng, L.; Inhester, B.; Wiegelmann, T.
Observations from the two STEREO-spacecraft give us for the first time the possibility to use stereoscopic methods to reconstruct the 3-D solar corona. Classical stereoscopy works best for solid objects with clear edges. Consequently an application of classical stereoscopic methods to the faint structures visible in the optically thin coronal plas…
X-ray emission from the M9 dwarf 1RXS J115928.5-524717. Quasi-quiescent coronal activity at the end of the main-sequence
Schmitt, J. H. M. M.; Robrade, J.
Aims: X-ray emission is an important diagnostic for studying magnetic activity in presumably fully convective, very low-mass stars with virtually neutral photospheres.
Methods: We analyse an XMM-Newton observation of 1RXS J115928.5-524717, an ultracool dwarf with spectral type M9, and compare its X-ray properties to those of other similar very…