Search Publications

Titan's rotation. A 3-dimensional theory
DOI: 10.1051/0004-6361:20077991 Bibcode: 2008A&A...478..959N

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…

2008 Astronomy and Astrophysics
Cassini 19
Abundances in planetary nebulae: NGC 6826
DOI: 10.1051/0004-6361:200809380 Bibcode: 2008A&A...483..519S

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…

2008 Astronomy and Astrophysics
ISO IUE eHST 19
Black Hole Accretion in Low-Mass Galaxies since z ~ 1
DOI: 10.1086/592192 Bibcode: 2008ApJ...688..794S

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…

2008 The Astrophysical Journal
XMM-Newton 19
Angular beaming model of Jupiter's decametric radio emissions based on Cassini RPWS data analysis
DOI: 10.1029/2008GL034987 Bibcode: 2008GeoRL..3517103I

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…

2008 Geophysical Research Letters
Cassini 19
The reconnection site of temporal cusp structures
DOI: 10.1029/2007JA012776 Bibcode: 2008JGRA..113.7S14T

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…

2008 Journal of Geophysical Research (Space Physics)
Cluster 19
A twelve-image gravitational lens system in the z ≃ 0.84 cluster Cl J0152.7-1357
DOI: 10.1051/0004-6361:200809434 Bibcode: 2008A&A...486...45G

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 …

2008 Astronomy and Astrophysics
eHST 19
The redshifted network contrast of transition region emission
DOI: 10.1051/0004-6361:200810490 Bibcode: 2008A&A...491L..13C

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…

2008 Astronomy and Astrophysics
SOHO 19
Multi-point observations of the inner boundary of the plasma sheet during geomagnetic disturbances
DOI: 10.1029/2008GL033982 Bibcode: 2008GeoRL..3517S23R

Dandouras, I.; Glassmeier, K. -H.; Nakamura, R. +6 more

We report on the THEMIS and Double Star TC-1 observations at the geocentric distances of 3 < R < 8 R E during substorms on March 23, 2007. THEMIS crossed the inner boundary of the equatorial dusk-side plasma in the string-of-pearls configuration, allowing the dynamics of particle populations to be traced within time ranges from h…

2008 Geophysical Research Letters
DoubleStar 19
The Origin of Polar Streamers in the Solar Corona
DOI: 10.1086/587924 Bibcode: 2008ApJ...680.1532Z

Llebaria, A.; Zhukov, A. N.; Lamy, P. +2 more

We investigate the large-scale three-dimensional (3D) structure of the solar corona near the maximum of the 23rd solar cycle in an attempt to determine the origin of polar streamers. We use a model that allows us to simulate the quasi-stationary configuration of the large-scale coronal density distribution. The coronal neutral line, as given by th…

2008 The Astrophysical Journal
SOHO 19
Measurement of Mass and Spin of Black Holes with QPOs
DOI: 10.48550/arXiv.0710.3454 Bibcode: 2008ChJAS...8..291A

Aschenbach, B.

There are now four low mass X-ray binaries with black holes which show twin resonant-like HFQPOs. Similar QPOs might have been found in Sgr A*. I review the power spectral density distributions of the three X-ray flares and the six NIR flares published for Sgr A* so far, in order to look for more similarities than just the frequencies between the …

2008 Chinese Journal of Astronomy and Astrophysics Supplement
XMM-Newton 19