Search Publications
Current carriers in the bifurcated tail current sheet: Ions or electrons?
Israelevich, P. L.; Ershkovich, A. I.; Oran, R.
We have studied statistical distributions of the current density in the geomagnetic tail current sheet for different sets of local plasma parameters using Cluster data. It is shown that the electric current density calculated from 4-point magnetic field measurements exhibits no correlation with the number flux of ions. We conclude that main curren…
The polyhedral nature of LINERs: an XMM-Newton view of LINERs in radio galaxies
Tavecchio, F.; Foschini, L.; Gliozzi, M. +1 more
Aims:We investigate the origin of X-rays and the nature of accretion flow in 4 low-ionization nuclear emission-line regions (LINERs) hosted by radio galaxies, namely NGC 1692, PKS 0625-35, 3C 88, 3C 444, recently observed with XMM-Newton.
Methods: We combine the results from the time-averaged spectral analysis with model-independent informatio…
Validation of Two MHD Models of the Solar Corona with Rotational Tomography
Sokolov, Igor V.; Hayashi, Keiji; Frazin, Richard A. +4 more
We demonstrate a validation of two 3D MHD models of the corona by comparing density values from solar rotational tomography (SRT) to densities and morphological properties of the two MHD solutions for CR 2029 (2005 April 21-May 18). The two MHD models are given by the Stanford and Michigan models, and both use the same synoptic magnetogram from MD…
Titan's rotation. A 3-dimensional theory
Vienne, A.; Noyelles, B.; Lemaître, A.
Aims:We study the forced rotation of Titan seen as a rigid body at the equilibrium Cassini state, involving the spin-orbit synchronization.
Methods: We used both the analytical and the numerical ways. We analytically determined the equilibrium positions and the frequencies of the 3 free librations around it, while a numerical integration assoc…
Abundances in planetary nebulae: NGC 6826
Pottasch, S. R.; Surendiranath, R.
Aims: We determine the chemical abundances and other parameters of the nebula NGC 6826 and its central star.
Methods: We present new ISO spectra and combine them with archival IUE and optical spectra from the literature to get a complete, extinction-corrected, spectrum. The chemical composition of the nebula is then calculated in two ways, fir…
Black Hole Accretion in Low-Mass Galaxies since z ~ 1
Rieke, George; Shi, Yong; Willmer, Christopher +3 more
We have selected a sample of X-ray-emitting active galactic nuclei (AGNs) in low-mass host galaxies (~5 × 109-2 × 1010 M⊙) out to z ~ 1. By comparing to AGNs in more massive hosts, we have found that the AGN spatial number density and the fraction of galaxies hosting AGNs depends strongly on the host mass, with the…
Angular beaming model of Jupiter's decametric radio emissions based on Cassini RPWS data analysis
Imai, Masafumi; Imai, Kazumasa; Higgins, Charles A. +1 more
Observations of the low frequency part of Jupiter decameter wavelength (DAM) emissions were made using the Cassini radio and plasma wave science (RPWS) instrument. We have analyzed non-Io-DAM occurrence dependence from 4 MHz to 16 MHz based on the System III central meridian longitude (CML) of the Cassini spacecraft and calculated the occurrence p…
The reconnection site of temporal cusp structures
Escoubet, C. P.; Yeoman, T. K.; Fuselier, S. A. +3 more
The strong precipitating particle flux in the cusp regions is the consequence of magnetic reconnection between the interplanetary magnetic field and the geomagnetic field. Magnetic reconnection is thought to be the dominant process for mass, energy, and momentum transfer from the magnetosheath into the magnetosphere. Observations of downward preci…
A twelve-image gravitational lens system in the z ≃ 0.84 cluster Cl J0152.7-1357
Demarco, R.; Lidman, C.; Grillo, C. +6 more
Context: Gravitational lens modeling is presented for the first discovered example of a three-component source for which each component is quadruply imaged. The lens is a massive galaxy member of the cluster Cl J0152.7-1357 at z ≃ 0.84.
Aims: Taking advantage of this exceptional configuration and of the excellent angular resolution of the HST …
The redshifted network contrast of transition region emission
Dwivedi, B. N.; Marsch, E.; Curdt, W. +1 more
Aims: We study the VUV emission of the quiet Sun and the net redshift of transition region lines in the SUMER spectral range. We aim at establishing a link with atmospheric processes and interpreting the observed downflow as the most evident part of the prevailing global coronal mass transport.
Methods: We rank and arrange all pixels of a mono…