Hydroxyl, water, ammonia, carbon monoxide and neutral carbon towards the Sagittarius A complex Hydroxyl, water, ammonia, carbon monoxide and neutral carbon towards the Sgr A complex
2013 (English)In: Proceedings of the International Astronomical UnionProceedings of the International Astronomical Union: The Galactic Center: Feeding and feedback in a normal galactic nucleus / [ed] Z. Knežević and A. Lemaitre, Cambridge University Press, 2013, Vol. 9, 97-99 p.Conference paper, Poster (Other academic)
We observed Hydroxyl, water, ammonia, carbon monoxide and neutral carbon towards the +50 km s−1 cloud (M−0.02−0.07), the circumnuclear disk (CND) and the +20 km s−1 (M−0.13−0.08) cloud in the Sgr A complex with the VLA, Odin and SEST. Strong OH absorption, H2O emission and absorption lines were seen at all three positions. Strong C18O emissions were seen towards the +50 and +20 km s−1 clouds. The CND is rich in H2O and OH, and these abundances are considerably higher than in the surrounding clouds, indicating that shocks, star formation and clump collisions prevail in those objects. A comparison with the literature reveals that it is likely that PDR chemistry including grain surface reactions, and perhaps also the influences of shocks has led to the observed abundances of the observed molecular species studied here. In the redward high-velocity line wings of both the +50 and +20 km s−1 clouds and the CND, the very high H2O abundances are suggested to be caused by the combined action of shock desorption from icy grain mantles and high-temperature, gas-phase shock chemistry. Only three of the molecules are briefly discussed here. For OH and H2O three of the nine observed positions are shown, while a map of the C18O emission is provided. An extensive paper was recently published with Open Access (Karlsson et al. 2013, A&A 554, A141).
Place, publisher, year, edition, pages
Cambridge University Press, 2013. Vol. 9, 97-99 p.
Astronomy, Astrophysics and Cosmology
Research subject Astronomy
IdentifiersURN: urn:nbn:se:su:diva-122688DOI: 10.1017/S174392131400026XOAI: oai:DiVA.org:su-122688DiVA: diva2:868116