Search Publications
Large-scale horizontal flows in the solar photosphere. III. Effects on filament destabilization
Bommier, V.; Schmieder, B.; Rondi, S. +7 more
Aims:We study the influence of large-scale photospheric motions on the destabilization of an eruptive filament, observed on October 6, 7, and 8, 2004, as part of an international observing campaign (JOP 178).
Methods: Large-scale horizontal flows were investigated from a series of MDI full-disc Dopplergrams and magnetograms. From the Dopplergr…
Penumbral models in the light of Hinode spectropolarimetric observations
Bellot Rubio, L. R.; Jurčák, J.
Aims:The realism of current models of the penumbra is assessed by comparing their predictions with the plasma properties of penumbral filaments as retrieved from spectropolarimetric observations.
Methods: The spectropolarimeter onboard Hinode allows us, for the first time, to distinguish the fine structure of the penumbra. Therefore, we can us…
The changing accretion states of the intermediate polar MU Camelopardalis
Krumpe, M.; Schwope, A. D.; Schwarz, R. +3 more
Aims: We study the timing and spectral properties of the intermediate polar MU Camelopardalis (1RXS J062518.2+733433) to determine the accretion modes and the accretion geometry from multi-wavelength, multi-epoch observational data.
Methods: Light curves in different observed energy ranges (optical, UV, X-ray) are extracted. The timescales of …
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…
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…
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…
The most rapidly rotating He-strong emission line star: HR 7355
Baade, D.; Rivinius, T.; Townsend, R. H. D. +1 more
Aims: We searched for massive stars with Balmer emission consistent with magnetically confined circumstellar material.
Methods: Archival spectroscopic and photometric data were investigated.
Results:
Time dependent model of the interplanetary Lyman α glow: applications to the SWAN data
Izmodenov, V.; Quémerais, E.; Koutroumpa, D. +1 more
Aims: Previous results of the study of interplanetary Lyman α background data obtained by the SWAN-SOHO between 1996 and 2005 clearly show that the solar cycle variations of the solar parameters deeply affect the interplanetary background emission. In this work, we compare these observational results with a time-dependent modeling of the interplan…