Search Publications
Shell-instability generated waves by low energy electrons on converging magnetic field lines
Vaivads, A.; Bogdanova, Y. V.; Décréau, P. M. E. +3 more
Wave emissions at electron cyclotron harmonics and at frequencies above the local plasma frequency are commonly observed in different magnetospheric regions. We show that such emissions when observed in the cusp, mantle or polar cap can be generated by shell-type electron distributions. We present an example of observations of such shell type dist…
Swift and XMM-Newton observations of the dark GRB 050326
Campana, S.; Tagliaferri, G.; Cusumano, G. +30 more
We present Swift and XMM-Newton observations of the bright gamma-ray burst GRB 050326, detected by the Swift Burst Alert Telescope. The Swift X-Ray Telescope (XRT) and XMM-Newton discovered the X-ray afterglow beginning 54 min and 8.5 h after the burst, respectively. The prompt GRB 050326 fluence was (7.7±0.9) × 10-6 erg cm-2…
The Morphology of Decimetric Emission from Solar Flares: GMRT Observations
Janardhan, P.; Kundu, M. R.; White, S. M. +3 more
Observations of a solar flare at 617 MHz with the Giant Meter-wave Radio Telescope (GMRT) are used to study the morphology of flare radio emission at decimetric wavelengths. There has been very little imaging in the 500 - 1000 MHz frequency range, but it is of great interest, since it corresponds to densities at which energy is believed to be rele…
Doppler redistribution of anisotropic radiation and resonance polarization in moving scattering media. Predicted results for the coronal O VI 1032 Å line
Raouafi, N. -E.; Sahal-Bréchot, S.
The present paper puts the Doppler redistribution theory of anisotropic radiation and resonance polarization in moving scattering media into a predictive application following Sahal-Bréchot et al. (1998, A&A, 340, 579; P{{II}}), using the example of the O VI 1032 Å line of the corona. Numerical results are presented for different heights over …
X-ray variability of NGC 2516 stars in the XMM-Newton observations
Micela, G.; Peres, G.; Marino, A. +1 more
We present the characteristics of the X-ray variability of stars in the cluster NGC 2516 as derived from XMM-Newton/EPIC/pn data. The X-ray variations on short (hours), medium (months), and long (years) time scales have been explored. We detected 303 distinct X-ray sources by analysing six EPIC/pn observations; 194 of them are members of the clust…
Time-Distance Measurements of Cross-Correlation Asymmetries around NOAA AR 10486
Thompson, Michael J.; Jensen, Jesper M.; Pijpers, Frank P.
We apply time-distance helioseismology to NOAA AR 10486 in order to examine the effect the presence of magnetic fields has on the resulting cross-correlations. Large-amplitude asymmetries between waves propagating in opposite directions are observed. The asymmetries can be attributed to suppression and absorption of seismic waves by the magnetic f…
Models of the protosatellite disk of Saturn: Conditions for Titan's formation
Dorofeeva, V. A.; Makalkin, A. B.
Models of the protosatellite accretion disk of Saturn are developed that satisfy cosmochemical constraints on the volatile abundances in the atmospheres of Saturn and Titan with due regard for the data obtained with the Cassini orbiter and the Huygens probe, which landed on Titan in January 2005. All basic sources of heating of the disk and protos…
The soft and hard X-ray emission of 3C 273 from 1996 to 2004 with BeppoSAX and XMM-Newton
Staubert, R.; Deluit, S. J.; Stuhlinger, M.
We present the results of a long monitoring of the quasar 3C 273 with BeppoSAX (1996 2001) and XMM-Newton (2000 2004). Our dataset is composed of nine BeppoSAX and 15 XMM observations for a total exposure time of 855 ks (∼492 ks for BeppoSAX and ∼363 ks for XMM). In the soft X-ray domain, we investigate the 2 10 keV continuum with MECS and PN and …
FH Leonis, the first dwarf nova member of a multiple star system?
Vogt, N.
Aims.Sudden brightenings of HD 96273 or BD+07 2411B were observed with the HIPPARCOS satellite in 1992, which still require a convincing explanation.
Methods: .A new analysis of all known data of these two stars is given, including additional information on the Balmer line equivalent widths.
Results: .The brightenings can be explained as S…
SMA gas release mechanism for the Rosetta Lander's Ptolemy instrument
Sawyer, Eric; Edeson, Ruben; Whalley, Martin +2 more
The Ptolemy instrument on the Rosetta comet lander “Philae” is an advanced gas analyser. The instrument relies on a supply of ultra-clean helium gas to carry cometary matter through a series of gas chromatography columns and high temperature reactors, into a mass spectrometer. The helium is stored in a pair of titanium gas tanks, pressurised to 50…