Search Publications
The FERRUM project: Experimental f-values for 4p-5s transitions in Fe II
Lundberg, H.; Li, Z. S.; Johansson, S. +2 more
New measurements of radiative lifetimes of four 3d65s levels in Fe II at about 10 eV are presented along with absolute oscillator strengths for twenty 4p-5s transitions involving the four levels. The experimental measurements are compared with two different sets of theoretical calculations. The lines are of particular interest in the mo…
Pick-up ions upstream and downstream of the termination shock
Fahr, H. J.; Hilchenbach, M.; Czechowski, A. +1 more
Hydrogen pick-up ions produced in the inner heliosphere are convected outwards with the solar wind and suffer energy-diffusion by quasilinear wave-particle interactions. When arriving at the solar wind termination shock, the big majority of these pick-up's passes directly from the preshock to the postshock plasma regime. While crossing the shock t…
Millimeter observations of radio-loud active galaxies
Bertoldi, F.; van Bemmel, I. M.
In order to study the nature of the far-infrared emission observed in radio-loud active galaxies, we have obtained 1.2 mm observations with the IRAM 30 m telescope for a sample of eight radio-loud active galaxies. In all objects we find that the 1.2 mm emission is dominated by non-thermal emission. An extrapolation of the non-thermal radio spectru…
An attempt to detect Vulcanoids with SOHO/LASCO images. I. Scale relativity and quantization of the solar system
Schumacher, G.; Gay, J.
We report an attempt to verify one of the predictions of Scale Relativity theory, namely that a small Vulcanoid should exist at 0.18 AU from the Sun. We have analyzed images taken by the coronograph LASCO aboard the satellite SOHO. Raw images are processed in order to eliminate cosmic ray impacts, stars and to improve the contrast. We have examine…
Modeling far-infrared emission from the HII region S125
Emery, R. J.; Aannestad, P. A.
We present ISO-LWS 45-180 mu m spectral observations at 17 positions in the HII region S125. We model, as one integrated region, the far-IR continuum emission as well as the observed emissions in the radio continuum and in the 21 cm line, comparing two different model density distributions and several silicate-carbon dust models. The dust in the H…
Proton transport through self-generated waves in impulsive flares
Vainio, R.; Kocharov, L.
Energetic proton transport through self-generated Alfvén waves in impulsive (gamma -ray) flares is studied using the method of Monte Carlo simulations. Protons are traced inside a flux tube after they are released from a point source located inside the loop until they hit the boundary of the 1-D simulation box and escape. As they stream from the s…
High angular resolution observations in the near infrared and modeling of the peculiar envelope of HD 62623
Danchi, W.; Lopez, B.; Monnier, J. D. +3 more
We report new observations of the peculiar star HD 62623 obtained with aperture masking interferometry performed on the Keck I telescope at lambda = 1.24, 1.65, 2.26 and 3.08 µm. The envelope around this star appears partially resolved in the near infrared except at 1.65 µm. Radiative transfer modeling of the dust shell of this star ha…
IUE and ISO observations of the bipolar proto-planetary nebula Hen 401 (IRAS 10178-5958)
Pottasch, S. R.; de Martino, D.; García-Lario, P. +5 more
We present ultraviolet (IUE) and infrared (ISO) observations of the bipolar proto-planetary nebula Hen 401 which, combined with previously available optical and near infrared data, are used to reconstruct the overall spectral energy distribution from 1150 Å to 100 mu m. The ISO spectrum is dominated by strong PAH emission superimposed on a very co…
Discovery of an absorbed cluster of galaxies (XMMU J183225.4-103645) close to the Galactic plane with XMM-Newton
Parmar, A. N.; Lumb, D.; Nevalainen, J. +3 more
During an XMM-Newton observation of the galactic supernova remnant G21.5-09 a bright, previously uncatalogued, source (XMMU J183225.4-103645) was detected 18' from G21.5-09. The European Photon Imaging Camera data inside 1' (180 h50-1 kpc) radius are consistent with a source at a redshift of 0.1242 +/- 0.00030…
An XMM-Newton view of the serendipitous sources in the PKS0312-770 field
Gondoin, P.; Guainazzi, M.; Lumb, D. H.
We describe an XMM-Newton observation of the PKS0312-770 field, which facilitates the spectral analysis of serendipitous sources previously detected by CHANDRA. The combination of larger effective area and longer exposure duration allows a significant increase in detected photons, and a lower limit in source detection sensitivity. In particular th…