Search Publications
Missions
Journals
Publication Years
Hybrid simulation of ion cyclotron resonance in the solar wind: Evolution of velocity distribution functions
Li, Xing; Habbal, Shadia R.
Resonant interaction between ions (oxygen ions O+5 and protons) and ion cyclotron waves is investigated using a one dimensional hybrid code. Ion cyclotron waves are self-consistently generated by an ion cyclotron anisotropy instability. We focus on the detailed acceleration process of ions. The energization of oxygen ions due to waves i…
Ion-Pressure Equations Derived from Measurements in Space
Stasiewicz, K.
Cluster measurements at the bow shock, the magnetosheath, and the magnetospheric boundary layer are used to derive ion-pressure equations for hot anisotropic plasmas. It is demonstrated that both perpendicular and parallel ion pressures are well approximated by polybaric expressions ∝NγBκ, where N is the plasma density, B is …
S/2004 S 5: A new co-orbital companion for Dione
Cooper, N. J.; Murray, C. D.; Evans, M. W. +1 more
We describe the astrometry and dynamics of S/2004 S 5 (provisionally named Polydeuces), a new satellite of Saturn, discovered in images recorded using the Imaging Science Subsystem (ISS) of the Cassini spacecraft. A total of 119 observations are presented, 101 of which were obtained with Cassini's narrow-angle camera and 18 using the wide-angle ca…
Determination of stellar shape in microlensing event MOA 2002-BLG-33
Bennett, D. P.; Cook, K. H.; Gal-Yam, A. +30 more
We report a measurement of the shape of the source star in microlensing event MOA 2002-BLG-33. The lens for this event was a close binary whose centre-of-mass passed almost directly in front of the source star. At this time, the source star was closely bounded on all sides by a caustic of the lens. This allowed the oblateness of the source star to…
Exo-Astrobiological Aspects of Europa and Titan: From Observations to Speculations
Raulin, François
By extrapolating what we know on the origins of life on Earth, and in particular on the chemical processes which gave rise to the first living system, Europa and Titan appear as two major targets for studies of exo/astrobiology in the outer solar system. With the likely presence of water oceans relatively close to its surface, coupled to possible …
XMM-Newton observation of the long-period polar V1309 Orionis: the case for pure blobby accretion
Burwitz, V.; Beuermann, K.; Schwarz, R. +1 more
Using XMM-Newton we have obtained the first continuous X-ray observation covering a complete orbit of the longest period polar, V1309 Ori. The X-ray light curve is dominated by a short, bright phase interval with EPIC pn count rates reaching up to 15 cts s-1 per 30 s resolution bin. The bright phase emission is well described by a singl…
Cluster vision of the magnetotail current sheet on a macroscale
Petrukovich, A. A.; Balogh, A.; Nakamura, R. +2 more
With Cluster 2001-2003 observations at ∼20 RE downtail we determine the cross-tail current sheet configuration via mapping of the neutral sheet positions and direct measurements of the sheet inclination. The warping effect tilts both flanks of the sheet up to 40° in the YZ GSM plane, while the gradual hinging effect tilts the sheet up t…
Long-Term INTEGRAL and RXTE Observations of the X-Ray Pulsar LMC X-4
Tsygankov, S. S.; Lutovinov, A. A.
We analyze the observations of the X-ray pulsar LMCX-4 performed by the INTEGRAL observatory and the All-Sky Monitor (ASM) of the RXTE observatory over a wide energy range. The observed hard X-ray flux from the source is shown to change by more than a factor of 50 (from ∼70 mCrab in the high state to ∼1.3 mCrab in the low state) on the time scale …
On the formation and evolution of magnetic chemically peculiar stars in the solar neighborhood
Paunzen, E.; Maitzen, H. M.; Pöhnl, H.
In order to put strict observational constraints on the evolutionary status of the magnetic chemically peculiar stars (CP2) of the upper main sequence, we have investigated a well established sample of galactic field CP2 objects within a radius of 200 pc from the Sun in the (X,Y) plane. In total, 182 stars with accurate parallax measurements from …
A new infrared view of evolved stars in IZw 18
Östlin, G.; Mouhcine, M.
We report results from near-infrared imaging of IZw 18, the most metal-poor galaxy in the local universe, with NICMOS on board the Hubble Space Telescope (HST). Observations were obtained in the broad F205W filter (~K) and in the medium-wide bands F171M and F180M, the latter which cover strong molecular absorption features in cool stars. The new d…