Search Publications
Common overabundance of 3He in high-energy solar particles
Torsti, J.; Kocharov, L.; Laivola, J.
Solar energetic particle (SEP) observations of the ERNE instrument (the Energetic and Relativistic Nuclei and Electron experiment) onboard the Solar and Heliospheric Observatory enable measurements of the 3He intensity in the high-energy range, >15 MeV nucleon-1, with a good statistical resolution. We report an overview of…
Photospheric flows measured with TRACE II. Network formation
Roudier, T.; Krijger, J. M.
We analyse a 7 d (167 h) sequence of TRACE white-light images with 1 arcsec angular resolution taken at 1 min cadence. The TRACE resolution and the fast cadence allows us to produce maps of the horizontal flow fields with high angular (1 arcsec) and temporal resolution (5 min). The field of view of 128arcsec x 128arcsec (~93 Mm x 93 Mm) covers app…
The corona of V390 Aurigae (HD 33798)
Gondoin, P.
V390 Aurigae (HD 33798) is a rapidly rotating, lithium rich, late-type giant whose distinctive characteristics include a high X-ray luminosity observed by the XMM-Newton space observatory. Series of lines of highly ionized Fe and several Lyman lines of hydrogen-like ions and triplet lines of helium-like ions are visible in the reflection grating s…
CDS/SoHO multi-line observation of a solar active region: Detection of a hot stable loop and of a cool dynamic loop
Peres, G.; Reale, F.; Di Giorgio, S.
We analyze a space-, time- and spectral-resolved SoHO/CDS observation of the evolution of an active region over a time lapse of approximately three hours in various spectral lines emitted in the interval of temperature 1.3 x 104 < T < 2.5 x 106 K. We identify and characterize two structures of interest: a longer coronal…
First results from TOO observations of the Aql X-1 field with INTEGRAL
Lutovinov, A.; Molkov, S.; Grebenev, S.
We present results of observations of the Aql X-1 field performed in March-April 2003 with the INTEGRAL observatory. This TOO (Target Of Opportunity) INTEGRAL observations was initiated upon receiving an indication from the ASM/RXTE that the source started an outburst. Thirteen X-ray sources were detected by the INTEGRAL imagers, JEM-X and IBIS, d…
Neutron-induced nuclear reactions and degradation in germanium detectors
Cordier, B.; Jean, P.; von Ballmoos, P. +15 more
We have measured cross sections of neutron-induced nuclear reactions leading to the delayed production of gamma -ray lines similar to the ones of astrophysical interest. Conclusions were drawn concerning the expected background in the 26Al 1809 keV line and the 7Be 478 keV line in SPI. The neutron-induced degradation of Ge de…
Status of the Integral/IBIS telescope modeling and of the response matrices generation
Goldoni, P.; Malaguti, G.; Bird, A. J. +8 more
The main objective of the IBIS modeling activities is the generation of the IBIS spectral response matrices. This generation has been done step by step by firstly constructing a ``calibrated model" of each IBIS sub-system. A ``calibrated model" is defined as a GEANT Monte-Carlo model, further checked by intensive corresponding calibration. These c…
Observation of GRB 030131 with the INTEGRAL satellite
Pian, E.; Frontera, F.; Hurley, K. +13 more
A long Gamma-Ray Burst (GRB) was detected with the instruments on board the INTEGRAL satellite on January 31 2003. Although most of the GRB, which lasted ~ 150 s, occurred during a satellite slew, the automatic software of the INTEGRAL Burst Alert System was able to detect it in near-real time. Here we report the results obtained with the IBIS ins…
Hyades dynamics from N-body simulations: Accuracy of astrometric radial velocities from Hipparcos
Madsen, Søren
The internal velocity structure in the Hyades cluster as seen by Hipparcos is compared with realistic N-body simulations using the NBODY6 code, which includes binary interaction, stellar evolution and the Galactic tidal field. The model allows to estimate reliably the accuracy of astrometric radial velocities in the Hyades as derived by Lindegren …
Propagation velocities of gas rings in collisional ring galaxies
Bizyaev, D.; Vorobyov, E. I.
The propagation velocity of the first gas ring in collisional ring galaxies, i.e. the velocity at which the maximum in the radial gas density profile propagates radially in the galactic disk, is usually inferred from the radial expansion velocity of gas in the first ring. Our numerical hydrodynamics modeling of ring galaxy formation however shows …