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An X-ray view of absorbed INTEGRAL AGN
de Rosa, A.; Walter, R.; Ubertini, P. +4 more
Aims: We present a 0.2-200 keV broadband study of absorbed Active Galactic Nuclei (AGN) observed with INTEGRAL, XMM-Newton, Chandra, and ASCA to investigate the continuum shape and the absorbing/reflecting medium properties.
Methods: The sources are selected in the INTEGRAL AGN sample to have a 20-100 keV flux below 8× 10-11 erg cm<…
A search for the most massive galaxies - II. Structure, environment and formation
Nichol, R. C.; Fritz, A.; Gebhardt, K. +3 more
We study a sample of 43 early-type galaxies, selected from the Sloan Digital Sky Survey (SDSS) because they appeared to have velocity dispersions of σ >= 350 km s-1. High-resolution photometry in the SDSS i passband using the High-Resolution Channel of the Advanced Camera for Surveys on board the Hubble Space Telescope shows that jus…
Soft X-Ray and Extreme Ultraviolet Excess Emission from Clusters of Galaxies
Kaastra, J. S.; Durret, F.; Werner, N. +2 more
An excess over the extrapolation to the extreme ultraviolet and soft X-ray ranges of the thermal emission from the hot intracluster medium has been detected in a number of clusters of galaxies. We briefly present each of the satellites (EUVE, ROSAT PSPC and BeppoSAX, and presently XMM-Newton, Chandra and Suzaku) and their corresponding instrumenta…
Hinode Observations of Chromospheric Brightenings in the Ca II H Line during Small-Scale Flux Emergence Events
Guglielmino, S. L.; Romano, P.; Bellot Rubio, L. R. +1 more
Ca II H emission is a well-known indicator of magnetic activity in the Sun and other stars. It is also viewed as an important signature of chromospheric heating. However, the Ca II H line has not been used as a diagnostic of magnetic flux emergence from the solar interior. Here we report on Hinode observations of chromospheric Ca II H brightenings…
Comet 67P/Churyumov-Gerasimenko at a large heliocentric distance
Tubiana, C.; Boehnhardt, H.; Drahus, M. +1 more
Aims: The Jupiter family comet 67P/Churyumov-Gerasimenko (67P/C-G) is the target comet of ESA's ROSETTA mission. A detailed portrait of this comet has been drawn from observations around perihelion, but what needs to be enhanced is the description of the comet's behaviour at large heliocentric distance. It is not only important for planning the re…
Behavior of current sheets at directional magnetic discontinuities in the solar wind at 0.72 AU
Russell, C. T.; Zhang, T. L.; Glassmeier, K. -H. +10 more
Venus Express interplanetary magnetic field measurements have been examined for magnetic ``holes,'' accompanied by magnetic field directional changes. We examine both the thickness of the current sheet and the depth of the magnetic field depression. We find the thickness of the current sheet is not correlated with the depth of the field depression…
Response of the inner magnetosphere and the plasma sheet to a sudden impulse
Zhang, T. L.; Dandouras, I.; RèMe, H. +11 more
The passage of an interplanetary shock caused a sudden compression of the magnetosphere between 0900 UT and 0915 UT on 24 August 2005. An estimate of the shock normal from solar wind data obtained by Geotail upstream of the bow shock indicates symmetric compression with respect to the noon-midnight meridian. Compression-related disturbances of the…
Field-aligned currents and parallel electric field potential drops at Mars. Scaling from the Earth’ aurora
Woch, J.; Dubinin, E.; Fraenz, M. +1 more
The observations of electron inverted 'V' structures by the MGS and MEX spacecraft, their resemblance to similar events in the auroral regions of the Earth, and the discovery of strong localized magnetic field sources of the crustal origin on Mars, raised hypotheses on the existence of Martian aurora produced by electron acceleration in parallel e…
The ChaMP Extended Stellar Survey (ChESS): Photometric and Spectroscopic Properties of Serendipitously Detected Stellar X-Ray Sources
Silverman, J. D.; Covey, K. R.; Barkhouse, W. A. +9 more
We present 348 X-ray-emitting stars identified from correlating the Extended Chandra Multiwavelength Project (ChaMP), a wide-area serendipitous survey based on archival X-ray images, with the Sloan Digital Sky Survey (SDSS). We use morphological star/galaxy separation, matching to an SDSS quasar catalog, an optical color-magnitude cut, and X-ray d…
Enceladus: A potential source of ammonia products and molecular nitrogen for Saturn's magnetosphere
Johnson, R. E.; Sittler, E. C.; Smith, H. T. +5 more
The detection of nitrogen species in Saturn's magnetosphere could, in principle, provide clues to the origin and evolution of its satellites and tenuous rings. Smith et al. (2005) first identified low-energy N+ using the Cassini Plasma Spectrometer (CAPS). N+ was predominantly seen in the Saturn's inner magnetosphere (<∼14…