Search Publications
ISO mid-infrared spectroscopy of Galactic Bulge AGB stars
Blommaert, J. A. D. L.; Ganesh, S.; Glass, I. S. +8 more
Aims.To study the nature of Bulge AGB stars and in particular their circumstellar dust, we have analysed mid-infrared spectra obtained with the ISOCAM CVF spectrometer in three Bulge fields.
Methods: .The ISOCAM 5-16.5 µm CVF spectra were obtained as part of the ISOGAL infrared survey of the inner Galaxy. A classification of the shape o…
The massive star population in the giant HII region Tol89 in NGC5398
Smith, Linda J.; Crowther, Paul A.; Sidoli, Fabrizio
We present new high spectral resolution Very Large Telescope (VLT)/UV-Visual Echelle Spectrograph (UVES) spectroscopy and archival Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) imaging and spectroscopy of the giant HII region Tol89 in NGC5398. From optical and ultraviolet (UV) HST images, we find that the star-forming co…
Vertical wind shear on Jupiter from Cassini images
West, Robert A.; Porco, Carolyn C.; Ingersoll, Andrew P. +5 more
Multifilter images of Jupiter acquired by the Cassini Imaging Science Subsystem (ISS) are used to derive zonal winds at altitudes above and below the visible cloud deck. Small features unique to the ultraviolet images of ISS are tracked to get the systematic high-altitude zonal winds. Comparison between the zonal winds from ultraviolet images and …
The Soft X-Ray Blast in the Apparently Subluminous GRB 031203
Foley, S.; Watson, D.; Fynbo, J. P. U. +11 more
GRB 031203 was a very low apparent luminosity γ-ray burst (GRB). Coincidentally, it was also the first GRB with a dust-scattered X-ray halo. The observation of the halo allowed us to infer the presence of a large soft X-ray fluence in the total burst output. It has also been claimed, however, that GRB 031203 was intrinsically subenergetic, represe…
Cluster observations of flux rope structures in the near-tail
Lucek, E.; Fazakerley, A. N.; Owen, C. J. +4 more
An investigation of the 2003 Cluster tail season has revealed small flux ropes in the near-tail plasma sheet of Earth. These flux ropes manifest themselves as a bipolar magnetic field signature (usually predominantly in the Z-component) associated with a strong transient peak in one or more of the other components (usually the Y-component). These …
The Jet and Circumnuclear Environment of 3C 293
O'Dea, Christopher P.; Axon, David J.; Sparks, William B. +5 more
We present new HST NIR polarimetry, broadband and narrowband imaging, and MERLIN 4.5 GHz multifrequency synthesis radio imaging of 3C 293, a unique radio galaxy whose host is an obvious merger remnant, in an exceptionally underdense region of space. We have discovered NIR, optical, and UV synchrotron emission from the jet. In the optical, the jet …
X-ray Observations of Binary and Single Wolf-Rayet Stars with XMM-Newton and Chandra
Güdel, Manuel; Schmutz, Werner; Zhekov, Svetozar +1 more
We present an overview of recent X-ray observations of Wolf-Rayet (WR) stars with XMM-Newton and Chandra. These observations are aimed at determining the differences in X-ray properties between massive WR + OB binary systems and putatively single WR stars. A new XMM spectrum of the nearby WN8 + OB binary WR 147 shows hard absorbed X-ray emission (…
ICMEs in the Outer Heliosphere and at High Latitudes: An Introduction
Richardson, J. D.; von Steiger, R.
Interplanetary coronal mass ejections (ICMEs) are observed at all latitudes and distances from which data are available. We discuss the radial evolution of ICMEs out to large distances and ICME properties at high latitudes. The internal pressure of ICMEs initially exceeds the ambient solar wind pressure and causes the ICMEs to expand in radial wid…
The influence of particle adhesion on the stability of agglomerates in Saturn's rings
Albers, Nicole; Spahn, Frank
In planetary rings, binary collisions and mutual gravity are the predominant particle interactions. Based on a viscoelastic contact model we implement the concept of static adhesion. We discuss the collision dynamics and obtain a threshold velocity for restitution or agglomeration to occur. The latter takes place within a range of a few cm s …
Near infra-red spectroscopy of the asteroid 21 Lutetia. I. New results of long-term campaign
Barucci, M. A.; Fulchignoni, M.; Vernazza, P. +4 more
Aims.Investigation of the physical nature of the asteroid 21 Lutetia, target of Rosetta mission, is required for the completion of its ground-based science and in the frame of its future fly-by. Monitoring this object is essential in preparing the future encounter with the spacecraft.
Methods: .The asteroid was observed with SpeX/IRTF in the s…