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Properties of RR Lyrae stars in the inner regions of the Large Magellanic Cloud
Cook, K. H.; Freeman, K. C.; Minniti, D. +3 more
We present the radial velocities, metallicities and the K-band magnitudes of 74 RR Lyrae stars in the inner regions of the LMC. The intermediate resolution spectra and infrared images were obtained with FORS1 at the ESO VLT and with the SOFI infrared imager at the ESO NTT. The best 43 RR Lyrae with measured velocities yield an observed velocity di…
An X-Ray Jet from a White Dwarf: Detection of the Collimated Outflow from CH Cygni with Chandra
Sokoloski, J. L.; Galloway, Duncan K.
Most symbiotic stars consist of a white dwarf accreting material from the wind of a red giant. An increasing number of these objects have been found to produce jets. Analysis of archival Chandra data of the symbiotic system CH Cygni reveals faint extended emission to the south, aligned with the optical and radio jets seen in earlier Hubble Space T…
Ultra-Compact Dwarf Galaxies in Galaxy Clusters
Ferguson, Henry C.; Drinkwater, Michael J.; Gregg, Michael D. +5 more
We review the evidence that the ultra-compact dwarf (UCD) galaxies we recently discovered in the Fornax Cluster form a new, previously unknown class of galaxies and we discuss possible scenarios for their formation. We then present recent results that UCDs are also present in the Virgo Cluster, and that there is a much larger than expected populat…
Density structures inside the plasmasphere: Cluster observations
André, M.; Santolik, O.; de Keyser, J. +11 more
Available from http://www.copernicus.org/site/EGU/annales/22/7/2577.htm?FrameEngine=false;
XMM-Newton discovery of a Compton-thick AGN in the GPS galaxy Mkn 668
Guainazzi, M.; Siemiginowska, A.; Rodriguez-Pascual, P. +1 more
We report the XMM-Newton discovery of the first Compton-thick obscured AGN in a Broad Line Radio Galaxy, the Gigahertz Peaked-Spectrum source Mkn 668 (OQ+208). The remarkably flat 2-10 keV X-ray spectrum (observed photon index, Γ ≃ 0.7), with a prominent iron Kα fluorescent emission line, is a clear signature of a Compton-reflection dom…
Helicity Patterns of Coronal Mass Ejection-associated Active Regions
Zhang, Jun; Wang, Jingxiu; Zhou, Guiping
Coronal mass ejections (CMEs) are thought to originate from the overaccumulation of magnetic helicity. While recent studies have revealed the inability of active region (AR) fields to create enough helicity for CMEs, we have tried, on the other hand, to examine whether particular helicity patterns are retained by CME-associated ARs. Nine ARs, whos…
Radar signal simulation: Surface modeling with the Facet Method
Safaeinili, A.; Kofman, W.; Herique, A. +1 more
A major finding in exploration of Mars is the indication that a large quantity of water has been present on Mars. To discover the distribution of this quantity of water, the Mars Express spacecraft is carrying a spaceborne radar sounder, called Mars Advance Radar for Subsurface and Ionospheric Sounding (MARSIS), in order to map Mars subsurface die…
Composition of the local interstellar medium as diagnosed with pickup ions
Gloeckler, George; Geiss, Johannes
Pickup ions provide us with a powerful tool to probe remote regions in and beyond the heliosphere and determine the composition of the neutral gas in these regions. Interstellar pickup ions, observed inside the heliosphere at 3-5 AU from the Sun, are created by charge exchange and photoionization of the local interstellar gas that penetrates deep …
Filtration of interstellar H, O, N atoms through the heliospheric interface: Inferences on local interstellar abundances of the elements
Geiss, J.; Gloeckler, G.; Izmodenov, V. +1 more
In this Letter we report on our study of the filtration of interstellar atoms of hydrogen, oxygen and nitrogen in the interaction region between the solar wind and the local interstellar medium. The filtration has great importance for the determination of local interstellar abundances of these elements, which becomes now possible due to measuremen…
Period and light variations for the cool, overcontact binary BX Pegasi
Han, Wonyong; Kim, Ho-Il; Lee, Jae Woo +2 more
New charge-coupled device photometric observations of the W UMa-type binary BX Pegasi (BX Peg) were collected on four nights from 1999 October to 2000 September. The light curve was covered completely in each season. Seven new times of minimum light were determined. It was found that the orbital period of the system has varied recently in a sinuso…