Search Publications
Interstellar Iron and Silicon Depletions in Translucent Sight Lines
Sofia, Ulysses J.; Meyer, David M.; Cartledge, Stefan I. B. +2 more
We report interstellar Fe II and Si II column densities toward six translucent sight lines (AV>~1) observed with the Space Telescope Imaging Spectrograph (STIS). The abundances were determined from the absorption of Si II] at 2335 Å, and several weak Fe transitions including the first reported detections of the λ2234 line. We derive …
Probing Space-Time in the Solar System:. from Cassini to Bepicolombo
Iess, Luciano; Asmar, Sami
Spacecraft radio science techniques can be used for precision solar system tests of relativistic gravity, as was demonstrated by the measurement of the Doppler shift of radio signals with the Cassini mission. Similar experiments are planned for the BepiColombo mission to Mercury. Recent theoretical developments based on string theory and inflation…
Quasi-Simultaneous Flux Emergence in the Events of October November 2003
Wang, Yuming; Wang, Jingxiu; Zhang, Yuzong +1 more
From late October to the beginning of November 2003, a series of intense solar eruptive events took place on the Sun. More than six active regions (ARs), including three large ARs (NOAA numbers AR 10484, AR 10486, and AR 10488), were involved in the activity. Among the six ARs, four of them bear obviously quasi-simultaneous emergence of magnetic f…
Measuring the dark matter velocity anisotropy in galaxy clusters
Piffaretti, R.; Hansen, S. H.
Aims:The Universe contains approximately 6 times more dark matter than normal baryonic matter, and directly observed fundamental difference between dark matter and baryons would both be significant for our understanding of dark matter structures and provide us with information about the basic characteristics of the dark matter particle. We discuss…
Needles in haystacks: how to use contemporaneous data in the search for low-frequency modes of oscillation of the Sun
Chaplin, W. J.; Elsworth, Y.; Appourchaux, T. +1 more
We show how to take advantage of contemporaneous data from two different instruments in the search for low-frequency modes of oscillation of the Sun. Contemporaneous data allow searches to be made for prominent, sharp concentrations of power which are coincident in frequency. Crucial to determining objective measures of the joint probability of th…
On Pitch-Angle Scattering Rates of Interstellar Pickup Ions as Determined by in Situ Measurement of Velocity Distributions
Bochsler, Peter; Möbius, Eberhard; Saul, Lukas +1 more
Newly ionized interstellar atoms are acted upon by electromagnetic forces in the solar wind. Measurements of these pickup ions enable study of the transport processes controlling the evolution of charged particle populations in solar wind plasma. Data from the CELIAS instruments on board the SOHO spacecraft allow measurement of the velocity distri…
Cluster observations of an auroral potential and associated field-aligned current reconfiguration during thinning of the plasma sheet boundary layer
Karlsson, T.; Marklund, G.; Johansson, T. +1 more
Cluster observations are used to illustrate the reconfiguration of an auroral potential structure encountered at the poleward boundary of the central plasma sheet within the Southern Hemisphere premidnight auroral oval. The reconfiguration from a symmetric U shape to an asymmetric S shape takes place between two consecutive crossings by Cluster sp…
Fine structure of decametric type II radio bursts
Konovalenko, A. A.; Chernov, G. P.; Stanislavsky, A. A. +3 more
We have performed a comparative analysis of the fine structure of two decametric type II bursts observed on July 17 and August 16, 2002, with the 1024-channel spectrograph of the UTR-2 radio telescope in the frequency range 18.5 29.5 MHz and with the IZMIRAN spectrograph in the frequency range 25 270 MHz. The August 16 burst was weak, ∼2 5 s.f.u.,…
On Solar Intermediate Drift Radio Bursts at Decimeter and Meter Wavelength
Mann, G.; Karlický, M.; Aurass, H. +2 more
Fiber - or intermediate drift - bursts are a continuum fine structure in some complex solar radio events. We present the analysis of such bursts in the X17 flare on 28 Oct. 2003. Based on the whistler wave model of fiber bursts we derive the 3D magnetic field structures that carry the radio sources in different stages of the event and obtain insig…
The long-term evolution and initial size of comets 46P/Wirtanen and 67P/Churyumov-Gerasimenko
Lamy, P. L.; Groussin, O.; Hahn, G. +2 more
We present a new method to study the long-term evolution of cometary nuclei in order to estimate their original size, and we consider the case of comets 46P/Wirtanen (hereafter 46P) and 67P/Churyumov-Gerasimenko (hereafter 67P). We calculate the past evolution of the orbital elements of both comets over 100000yr using a Bulirsch-Stoer integrator a…