Search Publications
First results obtained by the Cluster STAFF experiment
Maksimovic, M.; Chust, T.; de Conchy, Y. +20 more
The Spatio Temporal Analysis of Field Fluctuations (STAFF) experiment is one of the five experiments, which constitute the Cluster Wave Experiment Consortium (WEC). STAFF consists of a three-axis search coil magnetometer to measure magnetic fluctuations at frequencies up to 4 kHz, a waveform unit (up to either 10 Hz or 180 Hz) and a Spectrum Analy…
Galactic Bulges from Hubble Space Telescope Near-Infrared Camera Multi-Object Spectrometer Observations: The Lack of r1/4 Bulges
Balcells, Marc; Graham, Alister W.; Domínguez-Palmero, Lilian +1 more
We use Hubble Space Telescope (HST) near-infrared imaging to explore the shapes of the surface brightness profiles of bulges of S0-Sbc galaxies at high resolution. Modeling extends to the outer bulge via bulge-disk decompositions of combined HST-ground-based profiles. Compact, central unresolved components similar to those reported by others are f…
Composition and origin of the atmosphere of Jupiter - an update, and implications for the extrasolar giant planets
Wong, M. H.; Atreya, S. K.; Owen, T. C. +2 more
New developments have led to this update of the composition and origin of Jupiter's atmosphere that were originally discussed in our Planet. Space Sci. 47 (1999) 1243 paper. Since Jupiter can provide important insight into the atmospheres of extrasolar giant planets (EGP), we also discuss here the possible implications of the first detection of an…
Alfvénic Turbulence in the Extended Solar Corona: Kinetic Effects and Proton Heating
Cranmer, S. R.; van Ballegooijen, A. A.
We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Recent observations have shown that preferential heating and acceleration of positive ions occur in the first few solar radii of the high-speed solar wind. Measurements mad…
The Tycho-2 Spectral Type Catalog
Egan, Michael P.; Kraemer, Kathleen E.; Price, Stephan D. +1 more
The Tycho-2 Catalogue contains positions, proper motions, and BT and VT magnitudes for approximately 2.5 million stars. We have obtained spectral types for 351,864 of the Tycho-2 stars by cross-referencing Tycho-2 to several catalogs containing spectral types, using the VizieR astronomical database. The positional matching re…
Formation of polar ring galaxies
Bournaud, F.; Combes, F.
Polar ring galaxies are peculiar systems in which a gas-rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or by tidal accretion of the polar material from a gas rich donor galaxy. Both scenarios are studied…
Formation and development of shock waves in the solar corona and the near-Sun interplanetary space
Mann, G.; Classen, H. -T.; Aurass, H. +1 more
At the Sun, shock waves are produced either by flares and/or by coronal mass ejections (CMEs) and are regarded as the source of solar energetic particle events. They can be able to generate solar type II radio bursts. The non-radial propagation of a disturbance is considered away from an active region through the corona into the interplanetary spa…
Energetic particle acceleration and transport at coronal mass ejection-driven shocks
Li, Gang; Zank, G. P.; Rice, W. K. M.
Evidence now exists which suggests that in large solar energetic particle (SEP) events, particles are often accelerated to ∼ MeV energies (and perhaps up to GeV energies) at shock waves driven by coronal mass ejections (CMEs). These energetic particles are of considerable importance to space weather studies since they serve as a precursor signal f…
A Spectroscopic Survey of Subarcsecond Binaries in the Taurus-Auriga Dark Cloud with the Hubble Space Telescope
Hartigan, Patrick; Kenyon, Scott J.
We report the results of a spectroscopic survey of 20 close T Tauri binaries in the Taurus-Auriga dark cloud where the separations between primaries and their secondaries are less than the typical size of a circumstellar disk around a young star. Analysis of low- and medium-resolution Space Telescope Imaging Spectrograph spectra yields the stellar…
The iron line in MCG-6-30-15 from XMM-Newton: evidence for gravitational light bending?
Vaughan, S.; Fabian, A. C.
The lack of variability of the broad iron line seen in the Seyfert 1 galaxy MCG-6-30-15 is studied using the EPIC pn data obtained from a 2001 observation of 325 ks, during which the count rate from the source varied by a factor of 5. The spectrum of 80 ks of data from when the source was bright, using the lowest 10 ks as background, is well fitte…