Search Publications
Multi-Spacecraft Observations: Stream Interactions and Associated Structures
Luhmann, J. G.; Russell, C. T.; Jian, L. K. +2 more
The stream interaction region (SIR), formed when a fast stream overtakes a preceding slow stream, is the predominant large-scale solar wind structure at this early phase of the STEREO mission. Using multi-spacecraft observations from STEREO A and B, ACE, Wind, and Ulysses in 2007, we analyze three stream interaction events in depth in May, August,…
A Hubble Space Telescope/WFPC2 Survey of Bright Young Clusters in M31. III. Structural Parameters
Barmby, P.; Bellazzini, M.; Kissler-Patig, M. +6 more
Surface brightness profiles for 23 M31 star clusters were measured using images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope, and fitted to two types of models to determine the clusters' structural properties. The clusters are primarily young (~108 yr) and massive (~104.5 M sun), with median…
Solar Flare and CME Observations with STEREO/EUVI
Lemen, J. R.; Aschwanden, M. J.; Wuelser, J. P. +1 more
STEREO/EUVI observed 185 flare events (detected above the GOES class C1 level or at > 25 keV with RHESSI) during the first two years of the mission (December 2006 - November 2008), while coronal mass ejections (CMEs) were reported in about a third of these events. We compile a comprehensive catalog of these EUVI-observed events, containing the …
Discrepant Mass Estimates in the Cluster of Galaxies Abell 1689
Garmire, G. P.; Bautz, M. W.; Andersson, K. +1 more
We present a new mass estimate of a well studied gravitational lensing cluster, Abell 1689, from deep Chandra observations with a total exposure of 200 ks. Within r = 200 h -1 kpc, the X-ray mass estimate is systematically lower than that of lensing by 30%-50%. At r>200 h -1 kpc, the mass density profiles from X-ray and we…
Low-amplitude variations detected by CoRoT in the B8IIIe star HD 175869
Auvergne, M.; Chaintreuil, S.; Michel, E. +20 more
Context: The origin of the short-term variability in Be stars remains a matter of controversy. Pulsations and rotational modulation are the components of the favored hypothesis.
Aims: We present our analysis of CoRoT data of the B8IIIe star HD 175869 observed during the first short run in the center direction (SRC1).
Methods: We review bot…
Excess open solar magnetic flux from satellite data: 1. Analysis of the third perihelion Ulysses pass
Lockwood, M.; Owens, M.; Rouillard, A. P.
We use the third perihelion pass by the Ulysses spacecraft to illustrate and investigate the “flux excess” effect, whereby open solar flux estimates from spacecraft increase with increasing heliocentric distance. We analyze the potential effects of small-scale structure in the heliospheric field (giving fluctuations in the radial component on time…
Blazar nuclei in radio-loud narrow-line Seyfert 1?
Maraschi, L.; Ghisellini, G.; Tavecchio, F. +3 more
It has been suggested that some radio-loud narrow-line Seyfert 1 contain relativistic jets, on the basis of their flat-spectrum radio nuclei and studies on variability. We present preliminary results of an ongoing investigation of the X-ray and multiwavelength properties of 5 radio-loud NLS1 based on archival data from Swift and XMM-Newton. Some s…
The Topology and Behavior of Magnetic Fields Emerging at the Solar Photosphere
Lites, B. W.
The nature of flux emerging through the surface layers of the Sun is examined in the light of new high-resolution magnetic field observations from the Hinode space mission. The combination of vector magnetic field data and visible-light imaging from Hinode support the hypothesis that active region filaments are created as a result of an emerging, …
The updated spectral catalogue of INTEGRAL gamma-ray bursts
Götz, D.; Mereghetti, S.; Vianello, G.
We present a catalogue with the properties of all the bursts detected and localized by the IBIS instrument onboard the INTEGRAL satellite from November 2002 to September 2008. The sample is composed of 56 bursts, corresponding to a rate of ~0.8 GRB per month. Thanks to the performances of the INTEGRAL Burst Alert System, 50% of the IBIS GRBs have …
Thickness of Saturn's ring current determined from north-south Cassini passes through the current layer
Coates, A. J.; Cowley, S. W. H.; Bunce, E. J. +1 more
We investigate magnetic field and plasma electron data from six Cassini orbits during which, unique within the mission to date, the spacecraft passed almost directly north-south through Saturn's equatorial plane within the ring current region of the middle magnetosphere. Three passes took place in the postnoon sector and three took place in the po…