Search Publications
Electron acceleration by the reconnection outflow shock during solar flares
Mann, G.; Aurass, H.; Warmuth, A.
During solar flares a large amount of nonthermal electromagnetic radiation up to the γ-ray range is emitted from the corona, which implies that energetic electrons are generated. Within the framework of the magnetic reconnection scenario, jets appear in the outflow region and can establish standing fast-mode shocks if they penetrate the surroundin…
Modeling the Sun's open magnetic flux
Schüssler, M.; Baumann, I.
Context: .The heliospheric magnetic field can be extrapolated from the photospheric field distribution using models based upon various approximations. Such models are required for the reconstruction of the open solar magnetic flux prior to the time of direct measurements on the basis of surface flux transport simulations.
Aims: .We evaluate th…
Simulations of galactic winds and starbursts in galaxy clusters
van Kampen, E.; Schindler, S.; Breitschwerdt, D. +7 more
We present an investigation of the metal enrichment of the intra-cluster medium (ICM) by galactic winds and merger-driven starbursts. We use combined N-body/hydrodynamic simulations with a semi-numerical galaxy formation model. The mass loss by galactic winds is obtained by calculating transonic solutions of steady state outflows, driven by therma…
Radio and X-ray variability of young stellar objects in the Coronet cluster
Menten, K. M.; Forbrich, J.; Preibisch, Th.
The Coronet cluster in the nearby R CrA dark cloud offers the rare opportunity to study at least four "class I" protostellar sources as well as one candidate "class 0" source, a Herbig Ae star, and a candidate brown dwarf within a few square arcminutes - most of them detected at radio- and X-ray wavelengths. These sources were observed with the Ve…
Multiplicity of very low-mass objects in the Upper Scorpius OB association: a possible wide binary population
Béjar, V. J. S.; Schirmer, M.; Ghez, A. M. +5 more
Aims.Properties of multiplicity, such as the multiplicity frequency, the distribution of mass ratios and periods, provide important informations on the formation processes at work. Studying these properties in different environments and at different ages allows us to constrain the models of formation and to understand the influence of the environm…
26Al in the inner Galaxy. Large-scale spectral characteristics derived with SPI/INTEGRAL
Wang, W.; Strong, A. W.; Knödlseder, J. +12 more
Aims.We performed a spectroscopic study of the 1809 keV gamma-ray line from 26Al decay in the Galaxy using the SPI imaging spectrometer with its high-resolution Ge detector camera on the INTEGRAL observatory. Methods.We analyzed observations of the first two mission years, fitting spectra from all 7130 telescope pointings in narrow ener…
Observations in the Saturn system during approach and orbital insertion, with Cassini's visual and infrared mapping spectrometer (VIMS)
Sotin, C.; Brown, R. H.; Baines, K. H. +23 more
The Visual and Infrared Mapping Spectrometer observed Phoebe, Iapetus, Titan and Saturn's rings during Cassini's approach and orbital insertion. Phoebe's surface contains water ice, CO{2}, and ferrous iron. Iapetus contains CO{2} and organic materials. Titan's atmosphere shows methane fluorescence, and night-side atmospheric emission that may be C…
Using the ROSAT catalogues to find counterparts for the second IBIS/ISGRI survey sources
Walter, R.; Bird, A. J.; Ubertini, P. +6 more
The second IBIS/ISGRI survey has produced a catalogue containing 209 hard X-ray sources visible down to a flux limit of around 1 milliCrab. The point source location accuracy of typically 1-3 arcmin has allowed the counterparts for most of these sources to be found at other wavelengths. In order to help identify the remaining objects, we have used…
High-resolution millimeter-interferometer observations of the solar chromosphere
Solanki, S. K.; White, S. M.; Loukitcheva, M.
The use of millimeter-interferometer data for the study of chromospheric structure and dynamics is tested using 85 GHz observations with the 10-element Berkeley-Illinois-Maryland Array (BIMA). Interferometer data have the advantage over single-dish data that they allow both high spatial resolution and dense temporal sampling simultaneously. Howeve…
Discovery of PAHs in the halo of NGC 5907
Madden, S. C.; Irwin, J. A.
We have used sensitive archival data from the Infrared Space Observatory (ISO) to make maps of the edge-on low SFR galaxy, NGC 5907, in 6 different MIR bands: LW2, LW5, LW6, LW7, LW8, and LW10, covering the spectrum from 6.5 to 15.0 µm and including several narrow bands that isolate the infrared aromatic spectral features commonly referred t…