Search Publications
Statistical study of the quasi-perpendicular shock ramp widths
Krasnoselskikh, V.; Gedalin, M.; Hobara, Y. +2 more
The width of the collisionless shock front is one of the key shock parameters. The width of the main shock transition layer is related to the nature of the collisionless process that balances nonlinearity and therefore leads to the formation of the shock itself. The shock width determines how the incoming plasma particles interact with the macrosc…
The Western Libya Montes Valley System on Mars: Evidence for episodic and multi-genetic erosion events during the Martian history
Jaumann, R.; Tirsch, D.; Neukum, G. +2 more
A valley network in the Western Libya Montes region extending from 80°E to 83.4°E and 1.2°S to 3.9°N exhibits significant detail about water release processes and duration of erosional activities. The valley system originates at the southeastern offshoot of Syrtis Major and drains down to Isidis Planitia over a distance of about 300 km. Midstream,…
Magnetic field intensification: comparison of 3D MHD simulations with Hinode/SP results
Solanki, S. K.; Danilovic, S.; Schüssler, M.
Context. Recent spectro-polarimetric observations have provided detailed measurements of magnetic field, velocity and intensity during events of magnetic field intensification in the solar photosphere.
Aims: By comparing with synthetic observations derived from MHD simulations, we investigate the physical processes underlying the observations…
Magnetic anomalies near Apollinaris Patera and the Medusae Fossae Formation in Lucus Planum, Mars
Williams, David A.; Langlais, Benoit; Poulet, Francois +3 more
The nature of strong martian crustal field sources is investigated by mapping and modeling of Mars Global Surveyor magnetometer data near Apollinaris Patera, a previously proposed volcanic source, supplemented by large-scale correlative studies. Regional mapping yields evidence for positive correlations of orbital anomalies with both Apollinaris P…
New ephemeris of the ADC source 2A 1822-371: a stable orbital-period derivative over 30 years
Papitto, A.; Di Salvo, T.; Burderi, L. +4 more
We report on a timing of the eclipse arrival times of the low mass X-ray binary and X-ray pulsar 2A 1822-371 performed using all available observations of the Proportional Counter Array on board the Rossi X-ray Timing Explorer, XMM-Newton pn, and Chandra. These observations span the years from 1996 to 2008. Combining these eclipse arrival time mea…
Period-luminosity relations of pulsating M giants in the solar neighbourhood and the Magellanic Clouds
Derekas, A.; Kiss, L. L.; Bedding, T. R. +3 more
We analyse the results of a 5.5-yr photometric campaign that monitored 247 southern, semiregular variables with relatively precise Hipparcos parallaxes to demonstrate an unambiguous detection of red giant branch (RGB) pulsations in the solar neighbourhood. We show that Sequence A' contains a mixture of asymptotic giant branch and RGB stars, as ind…
Detection of a Pseudobulge Hidden Inside the "Box-shaped Bulge" of NGC 4565
Kormendy, John; Barentine, John C.
Numerical simulations show that box-shaped bulges of edge-on galaxies are not bulges: they are bars seen side-on. Therefore, the two components that are seen in edge-on Sb galaxies such as NGC 4565 are a disk and a bar. But face-on SBb galaxies always show a disk, a bar, and a (pseudo)bulge. Where is the (pseudo)bulge in NGC 4565? We use archival …
The multifrequency campaign on 3C 279 in January 2006
Burwitz, V.; Bremer, M.; Gurwell, M. +7 more
Context. The prominent blazar 3C 279 is known for its large-amplitude variability throughout the electromagnetic spectrum and its often γ-ray-dominated spectral energy distribution. However, the characterization of its broadband spectral variability still lacks a consistent picture, and the origin of its high-energy emission is still unclear.
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Three-Dimensional Polarimetric Coronal Mass Ejection Localization Tested Through Triangulation
Thompson, William T.; Davila, Joseph M.; Moran, Thomas G.
We have tested the validity of the coronal mass ejection (CME) polarimetric reconstruction technique for the first time using triangulation and demonstrated that it can provide the angle and distance of CMEs to the plane of the sky. In this study, we determined the three-dimensional orientation of the CMEs that occurred on 2007 August 21 and 2007 …
A Method for Measuring Variations in the Stellar Initial Mass Function
Calzetti, D.; Kennicutt, R. C.; Lee, J. C. +3 more
We present a method for investigating variations in the upper end of the stellar initial mass function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages <=107 yr and with different masses. We test this method by performing a pilot study on the young cluster population in the nearb…