Fabrice Herpin

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Knowledge about the outermost portions of galaxies is limited owing to the small amount of light coming from them. It is known that in many cases atomic hydrogen (H I) extends well beyond the optical radius. In the centres of galaxies, however, molecular hydrogen (H2) usually dominates by a large factor, raising the question of whether H2 is also abundant(More)
Context. The study of physical and chemical properties of massive protostars is critical to better understand the evolutionary sequence which leads to the formation of high-mass stars. Aims. IRAS 18151−1208 is a nearby massive region (d = 3 kpc, L ∼ 2×10 4 L) which splits into three cores: MM1, MM2 and MM3 (separated by 1 –2). We aim at (1) studying the(More)
Context. The origin of magnetism around asymptotic giant branch (AGB) stars is still uncertain. If these stars drive a dynamo, it cannot be sufficiently efficient to generate a strong global field, otherwise the observed X-ray luminosities would be higher. Other explanations for the circular polarization of SiO masers in the AGB atmospheres are thus needed.(More)
  • Thijs de Graauw, Nick Whyborn, +72 authors Peer Zaal
  • 2008
This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI), to be launched onboard of ESA's Herschel Space Observatory, by 2008. It includes the first results from the instrument level tests. The instrument is designed to be electronically tuneable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions(More)
We present detailed observations of the 1.2 mm continuum and the CO line emission in the exceptional star-burst/active galaxy NGC 3079 with the IRAM 30-m telescope. The 1.2 mm thermal dust emission is much less centrally concentrated than the CO or radio continuum. Roughly 10% of the total 1.2 mm flux comes from the central 11 as opposed to ∼ 40% for the CO(More)
Context. The origin of magnetism around asymptotic giant branch (AGB) stars is still uncertain. These stars may drive an important dynamo, but if the magnetic energy dissipates all in X-rays, the observed X-ray luminosities are too low for a strong, dynamically important global field. Other explanations for the circular polarization of SiO masers in the AGB(More)
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