Fabrice Herpin

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We report on the detection with the Infrared Space Observatory (ISO), for the first time in the circumstellar medium, of the polyacetylenic chains C4H2 and C6H2 and of benzene (C6H6) in the direction of the proto–planetary nebula CRL 618. Surprisingly, the abundances of diand triacetylene are only a factor of 2–4 lower than that of C2H2. Benzene is .40(More)
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. Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time thanks to the Herschel Space Observatory. Ionized hydrides such as CH and OH (and also HCO), which affect the(More)
We present ISO LWS observations of the proto-planetary nebula CRL 618, a star evolving very fast to the planetary nebula stage. In addition to the lines of CO , CO , HCN and HNC, we report on the detection of H2O and OH emission together with the fine structure lines of [OI] at 63 and 145 μm. The abundance of the latter three species relative to CO are 4(More)
“Water In Star-forming regions with Herschel” (WISH) is a key programme dedicated to studying the role of water and related species during the star-formation process and constraining the physical and chemical properties of young stellar objects. The Heterodyne Instrument for the FarInfrared (HIFI) on the Herschel Space Observatory observed three deeply(More)
Aims. Previous studies by the satellites SWAS and Odin provided stringent upper limits on the gas phase water abundance of dark clouds (x(H 2O) < 7 × 10−9). We investigate the chemistry of water vapor in starless cores beyond the previous upper limits using the highly improved angular resolution and sensitivity of Herschel and measure the abundance of water(More)
  • F. F. S. van der Tak, M. G. Marseille, F. Herpin
  • 2010
Context. Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known. Aims. We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming region with a powerful outflow and a compact H ii region. Methods. Herschel-HIFI spectra near 1100 GHz show(More)
We present detailed observations of the 1.2mm continuum and the CO line emission in the exceptional starburst/active galaxy NGC 3079 with the IRAM 30-m telescope. The 1.2mm thermal dust emission is much less centrally concentrated than the CO or radio continuum. Roughly 10% of the total 1.2mm flux comes from the central 11′′ as opposed to ∼ 40% for the CO(More)
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)