H2CO in the Horsehead PDR: photo-desorption of dust grain ice mantles
نویسندگان
چکیده
منابع مشابه
Sulfur chemistry in the Horsehead An interferometric view of the Horsehead PDR
Sulfur is an abundant element which remains undepleted in diffuse interstellar gas (AV < 1) but it is traditionally assumed to deplete on dust grains at higher densities and larger AV . Photodissociation regions (PDRs) are an interesting intermediate medium between translucent and dark clouds where the chemistry and energetics are dominated by the illuminating FUV radiation field. Thus they can...
متن کاملIce in space: surface science investigations of the thermal desorption of model interstellar ices on dust grain analogue surfaces.
More than 140 different molecules have been identified in the interstellar medium (ISM) to date. Dust grain particles are also found in the ISM, and some of these molecules freeze out at the cold temperatures (10-20 K) to form molecular ices. Understanding the adsorption and desorption of these ices is crucially important in understanding the processes that lead to star and planet formation, an...
متن کاملHCO mapping of the Horsehead : Tracing the illuminated dense molecular cloud surfaces
Context. Far-UV photons strongly affect the physical and chemical state of molecular gas in the vicinity of young massive stars. Aims. Finding molecular tracers of the presence of FUV radiation fields in the millimeter wavelength domain is desirable, because IR diagnostics (PAHs for instance) are not easily accessible towards high extinction line-of-sights. Furthermore, gas phase diagnostics pr...
متن کاملDiscovery of solid HDO in grain mantles ?
The observation of deuterium fractionation in the molecular gas in hot cores is currently interpreted as evaporation of deuterium-rich molecules from the icy grain mantles where they accumulated during the cold, dense cloud core stage. The predicted enrichment in deuterium of the ices has never been observed. This work provides the rst detections of solid HDO in grain mantles. We nd column dens...
متن کاملDensity structure of the Horsehead nebula photo-dissociation region
We present high angular resolution images of the H2 1-0 S(1) line emission obtained with the Son of ISAAC (SOFI) at the New Technology Telescope (NTT) of the Horsehead nebula. These observations are analysed in combination with Hα line emission, aromatic dust, CO and dust continuum emissions. The Horsehead nebula illuminated by the O9.5V star σ Ori (χ ∼ 60) presents a typical photodissociation ...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2011
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201117257