Search Publications
Comparison of multi-point measurements of current sheet structure and analytical models
Malova, H. V.; Petrukovich, A. A.; Zelenyi, L. M. +5 more
Current density profiles of 22 thin current sheets, crossed by four Cluster spacecraft in the magnetotail are compared with the self-consistent model of anisotropic 1-D equilibrium, including several species of quasi-adiabatic (transient) ions and drifting electrons. In order to examine ion-scale features of the current density profile Cluster dat…
Dynamics of coronal mass ejections. The mass-scaling of the aerodynamic drag
Vršnak, B.; Vrbanec, D.; Čalogović, J.
Context: Coronal and interplanetary propagation of coronal mass ejections (CMEs) is strongly affected by aerodynamic drag.
Aims: The dependence of the drag acceleration on the mass of the CMEs is investigated to establish a quantitative empirical relationship, which might be important in semi-empirical space-weather forecasting.
Methods: W…
Solar off-limb line widths: Alfvén waves, ion-cyclotron waves, and preferential heating
Dolla, L.; Solomon, J.
Context: Alfvén waves and ion-cyclotron absorption of high-frequency waves are frequently brought into models devoted to coronal heating and fast solar-wind acceleration. Signatures of ion-cyclotron resonance have already been observed in situ in the solar wind (HELIOS spacecrafts) and, recently, in the upper corona (UVCS/SOHO remote-sensing resul…
A bright, dust-obscured, millimetre-selected galaxy beyond the Bullet Cluster (1E0657-56)
Yun, M. S.; Kohno, K.; Wilson, G. W. +24 more
Deep 1.1mm continuum observations of 1E0657-56 (the `Bullet Cluster') taken with the millimeter-wavelength camera AzTEC on the 10-m Atacama Submillimeter Telescope Experiment (ASTE), have revealed an extremely bright (S1.1mm = 15.9mJy) unresolved source. This source, MMJ065837-5557.0, lies close to a maximum in the density of underlying…
Rise of a Dark Bubble through a Quiescent Prominence
de Toma, G.; Burkepile, J. T.; Low, B. C. +1 more
We report on a dynamical event observed in a quiescent prominence on 2007 November 8: a well-formed dark "bubble" with a bright core rose vertically through the prominence without causing it to erupt. This event was observed in Hα and He I 1083 nm with the instruments of the Mauna Loa Solar Observatory. The dark bubble had a size of over 40'' and …
XMM-Newton observations of the diffuse X-ray emission in the starburst galaxy NGC 253
Pietsch, W.; Read, A. M.; Freyberg, M. J. +4 more
Aims: We present a study of the diffuse X-ray emission in the halo and the disc of the starburst galaxy NGC 253.
Methods: After removing point-like sources, we analysed XMM-Newton images, hardness ratio maps and spectra from several regions in the halo and the disc. We introduce a method to produce vignetting corrected images from the EPIC pn …
A swarm of small shield volcanoes on Syria Planum, Mars
Williams, David A.; Mangold, Nicolas; Bleacher, Jacob E. +7 more
This study focuses on the volcanism in Syria Planum, located at the center of the Tharsis bulge at an altitude of 6 to 8 km above Mars datum. Syria Planum was previously recognized as a center for the tectonic activity of Tharsis, but not as a major locus for volcanic activity, despite its centrality over the bulge. Using high-resolution images fr…
Modelling the Venusian airglow
Leblanc, F.; Gronoff, G.; Lilensten, J. +3 more
Context: Modelling of the Venusian ionosphere fluorescence is required, to analyse data being collected by the SPICAV instrument onboard Venus Express.
Aims: We present the modelling of the production of excited states of O, CO and N2, which enables the computation of nightglow emissions. In the dayside, we compute several emissions, taking ad…
Supergranules over the solar cycle
Meunier, N.; Roudier, T.; Rieutord, M.
Context: The origin of supergranulation has not been understood yet. Contradictory results have been obtained in the past concerning the relation between supergranule properties (mostly cell size) and the solar cycle.
Aims: We propose to study the variation in supergranule cell sizes and velocity fields over the solar cycle, as well as the int…
Biases on Initial Mass Function Determinations. II. Real Multiple Systems and Chance Superpositions
Maíz Apellániz, J.
When calculating stellar initial mass functions (IMFs) for young clusters, one has to take into account that (1) most massive stars are born in multiple systems, (2) most IMFs are derived from data that cannot resolve such systems, and (3) multiple chance superpositions between members are expected to happen if the cluster is too distant. In this …