Ref: ASTROimport-445

Silicon in the dust formation zone of IRC +10216

Decin, L. ; Cernicharo, J. ; Barlow, M. J. ; Royer, P. ; Vandenbussche, B. ; Wesson, R. ; Polehampton, E. T. ; De Beck, E. ; Agúndez, M. ; Blommaert, J. A. D. L. ; Cohen, M. ; Daniel, F. ; De Meester, W. ; Exter, K. ; Feuchtgruber, H. ; Fonfría, J. P. ; Gear, W. K. ; Goicoechea, J. R. ; Gomez, H. L. ; Groenewegen, M. A. T. ; Hargrave, P. C. ; Huygen, R. ; Imhof, P. ; Ivison, R. J. ; Jean, C. ; Kerschbaum, F. ; Leeks, S. J. ; Lim, T. ; Matsuura, M. ; Olofsson, G. ; Posch, T. ; Regibo, S. ; Savini, G. ; Sibthorpe, B. ; Swinyard, B. M. ; Tercero, B. ; Waelkens, C. ; Witherick, D. K. ; Yates, J. A.

published in Astronomy and Astrophysics, 518, pp. L143 (2010)

Abstract: The interstellar medium is enriched primarily by matter ejected from evolved low and intermediate mass stars. The outflows from these stars create a circumstellar envelope in which a rich gas-phase and dust-nucleation chemistry takes place. We observed the nearest carbon-rich evolved star, IRC +10216, using the PACS (55-210 µm) and SPIRE (194-672 µm) spectrometers on board Herschel. We find several tens of lines from SiS and SiO, including lines from the v = 1 vibrational level. For SiS these transitions range up to J = 124-123, corresponding to energies around 6700 K, while the highest detectable transition is J = 90-89 for SiO, which corresponds to an energy around 8400 K. Both species trace the dust formation zone of IRC +10216, and the broad energy ranges involved in their detected transitions permit us to derive the physical properties of the gas and the particular zone in which each species has been formed. This allows us to check the accuracy of chemical thermodynamical equilibrium models and the suggested depletion of SiS and SiO due to accretion onto dust grains. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix is only available in electronic form at http://www.aanda.org

DOI: 10.1051/0004-6361/201014562
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The record appears in these collections:
Royal Observatory of Belgium > Astronomy & Astrophysics
Science Articles > Peer Reviewed Articles

 Record created 2016-07-01, last modified 2016-07-06