First NH3 detection of the Orion Bar

• Main Authors: Larsson, B, Liseau, R, Bergman, P, Bernath, P, Black, J. H, Booth, R. S, Buat, V, Curry, C. L, Encrenaz, P, Falgarone, E, Feldman, P, Fich, M, Flore'n, H. G, Frisk, U, Gerin, M, Gregersen, E. M, Harju, J, Hasegawa, T, Johansson, L. E. B, Kwok, S, Lecacheux, A, Liljestrom, T, Mattila, K, Mitchell, G. F, Nordh, L. H, Olberg, M, Olofsson, G, Pagani, L, Plume, R, Ristorcelli, I, Sandqvist, Aa, Sche'ele, F. v, Tothill, N. F. H, Volk, K, Wilson, C. D, Hjalmarson, A
• Format: Journal Article
• Language: English
• Published: 05-03-2003
• Subjects: Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.astro-ph/0303122

Astron.Astrophys. 402 (2003) L69-L72 Odin has successfully observed three regions in the Orion A cloud, i.e. Ori
KL, Ori S and the Orion Bar, in the 572.5 GHz rotational ground state line of
ammonia, ortho-NH3 (J,K) = (1,0) -> (0,0), and the result for the Orion Bar
represents the first detection in an ammonia line. Several velocity components
are present in the data. Specifically, the observed line profile from the Orion
Bar can be decomposed into two components, which are in agreement with
observations in high-J CO lines by Wilson et al. 2001. Using the source model
for the Orion Bar by these authors, our Odin observation implies a total
ammonia abundance of NH3/H2 = 5E-9.