Search Publications
Oxygen-rich disk in the V778 Cygni system resolved
Szczerba, R.; Richards, A. M. S.; Poutanen, J. +3 more
Aims.Various scenarios have been proposed to explain the presence of silicate features associated with carbon stars, such as
Methods: .The 22 GHz water maser emission from this star has been mapped using MERLIN wit…
Double-barred galaxies at intermediate redshifts: a feasibility study
Lisker, Thorsten; Debattista, Victor P.; Ferreras, Ignacio +1 more
Despite the increasing number of studies of barred galaxies at intermediate and high redshifts, double-barred (S2B) systems have only been identified in the nearby (z <= 0.04) universe thus far. In this feasibility study, we demonstrate that the detection and analysis of S2Bs is possible at intermediate redshifts (0.1 <~ z <~ 0.5) with th…
The Blue Straggler Population of the Globular Cluster M5: Comparison with M3
Warren, Steven R.; Bolte, Michael; Sandquist, Eric L.
We have surveyed the blue straggler star population of the Galactic globular cluster M5 using high-resolution images of the core along with wide-field ground-based images reaching to more than 19 core radii. To gauge M5's relative efficiency of producing stragglers, we compared our sample to five studies of other globular clusters. Using a ``brigh…
Chandra Observation of NGC 6822
Tennant, Allyn F.
Chandra observed the nearby dwarf galaxy NGC 6822. There are 70 sources in the Chandra field, two of which are fairly extended and likely background clusters of galaxies. A third source was resolved by Chandra that has the same size and position as a known supernova remnant. The suspected variability detected from this source in previous missions …
The Gradual Phase of the X17 Flare on October 28, 2003
Schmieder, B.; Berlicki, A.; del Zanna, G. +2 more
We present SOHO/CDS observations taken during the gradual phase of the X17 flare that occurred on October 28, 2003. The CDS data are supplemented with TRACE and ground-based observations. The spectral observations allow us to determine velocities from the Doppler shifts measured in the flare loops and in the two ribbon kernels, one hour and a half…
Temporal and Spatial Relationships between Ultraviolet and Hard X-Ray Emission in Solar Flares
Alexander, David; Coyner, Aaron J.
Hard X-ray and ultraviolet emissions in solar flares provide evidence for the interaction of particles accelerated in the solar corona with the ambient plasma in the chromosphere. Previous studies have shown that these emissions are temporally correlated indicating a common source, presumably magnetic reconnection, governing the flare energy relea…
Plasma wave source location using CLUSTER as a spherical wave telescope
Glassmeier, K. -H.; Motschmann, U.; FräNz, M. +3 more
The use of sensor arrays in space opens up the possibility to investigate the source location of plasma waves. In order to do so, we generalize the wave telescope technique to use spherical waves instead of plane waves. The new tool determines the center of the wavefronts locally measured by the sensor array. This virtual source can be related wit…
IMF Direction Derived from Cycloid-Like Ion Distributions Observed by Mars Express
Coates, A. J.; Kallio, E.; Fedorov, A. +29 more
Although the Mars Express (MEX) does not carry a magnetometer, it is in principle possible to derive the interplanetary magnetic field (IMF) orientation from the three dimensional velocity distribution of pick-up ions measured by the Ion Mass Analyser (IMA) on board MEX because pick-up ions' orbits, in velocity phase space, are expected to gyrate …
A test-particle model of the atmosphere/ionosphere system of Saturn's main rings
Tokar, R. L.; Johnson, R. E.; Young, D. T. +4 more
The first pass of the Cassini orbiter near the A and B rings of Saturn, formed mainly by H2O ice particles, revealed the presence of an ionosphere composed of O+ and O2+ ions. Such a result suggests the existence of an atmospheric halo made up of molecular oxygen surrounding the rings. It is produced by …
ISS-SOLAR: Total (TSI) and spectral (SSI) irradiance measurements
Fröhlich, C.; Thuillier, G.; Schmidtke, G.
The primary objective of the ISS-SOLAR mission on Columbus (to be launched in 2006) is the quasi-continuous measurement of the solar irradiance variability with highest possible accuracy. For this reason the total spectral range will be recorded simultaneously from 3000 to 17 nm by three sets of instruments: SOVIM is combining two types of absolut…