Chemical evolution ahead of Herbig–Haro objects |
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| Authors: | Serena Viti David A Williams |
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| Institution: | Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT |
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| Abstract: | Compact regions of enhanced HCO+ and NH3 emission have been detected close to a number of Herbig–Haro objects. An interpretation of these detections is the following: a transient clump within the molecular cloud has been irradiated by the shock that generates the Herbig–Haro object. The irradiation releases icy mantles from the grains within the transient clump and initiates a photochemistry. On the basis of this picture, we have developed an extensive chemical model which predicts that a wide range of species, other than NH3 and HCO+, should also be detectable. These include CH3OH, H2S, C3H4, H2CO, SO, SO2, H2CS and NS. The chemical effects should last ～ 104 yr . |
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| Keywords: | molecular processes ISM: clouds ISM: jets and outflows ISM: molecules |
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