Odin water mapping in the Orion KL region
Journal article, 2003
New results from water mapping observations of the Orion KL region using the submm/mm wave satellite Odin (2.1′ beam size at 557 GHz), are presented. The ortho-H2O JK(+)K(-) = l1.0 → l0.1 ground state transition was observed in a 7′ × 7′ rectangular grid with a spacing of 1′, while the same line of H218O was measured in two positions, Orion KL itself and 2′ south of Orion KL. In the main water species, the KL molecular outflow is largely resolved from the ambient cloud and it is found to have an extension of 60″-110″. The H2O outflow profile exhibits a rather striking absorption-like asymmetry at the line centre. Self-absorption in the near (or "blue") part of the outflow (and possibly in foreground quiescent halo gas) is tentatively suggested to play a role here. We argue that the dominant part of the KL H218O outflow emission emanates from the compact (size ∼15″) low-velocity flow and here estimate an H2O abundance of circa 10-5 compared to all H2 in the flow - an order of magnitude below earlier estimates of the H2O abundance in the shocked gas of the high-velocity flow. The narrow ambient cloud lines show weak velocity trends, both in the N-S and E-W directions. H218O is detected for the first time in the southern position at a level of ∼0.15 K and we here estimate an H2O abundance of (1-8) × 10-8.
ISM: abundances
ISM: individual objects: Orion KL
ISM: molecules
Submillimeter
Author
Henrik Olofsson
Onsala Space Observatory
G. Olofsson
Stockholm Observatory
Åke Hjalmarson
Chalmers, Onsala Space Observatory
Per Bergman
Chalmers, Onsala Space Observatory
John H Black
Chalmers, Onsala Space Observatory
Roy Booth
Chalmers, Onsala Space Observatory
V. Buat
C.L. Curry
University of Waterloo
P. J. Encrenaz
Paris Observatory
E. Falgarone
Ecole Normale Superieure (ENS)
P. Feldman
M. Fich
University of Waterloo
H. G. Floren
Stockholm Observatory
U. Frisk
Swedish Space Corporation (SSC)
M. Gerin
Ecole Normale Superieure (ENS)
E.M. Gregersen
McMaster University
J. Harju
University of Helsinki
T. Hasegawa
University of Calgary
Lars E B Johansson
Chalmers, Onsala Space Observatory
S. Kwok
University of Calgary
B. Larsson
Stockholm Observatory
A. Lecacheux
Observatoire de Paris-Meudon
T Liljeström
René Liseau
Stockholm Observatory
K. Mattila
University of Helsinki
G.F. Mitchell
Saint Mary's University
H. L. Nordh
Swedish National Space Board
Michael Olberg
Chalmers, Onsala Space Observatory
H. Olofsson
Stockholm Observatory
L. Pagani
Paris Observatory
R. Plume
University of Calgary
I. Ristorcelli
Gustaf Rydbeck
Chalmers, Onsala Space Observatory
Aa. Sandqvist
Stockholm Observatory
F. von Scheele
Swedish Space Corporation (SSC)
G. Serra
N.F. Tothill
Saint Mary's University
K. Volk
University of Calgary
C. D. Wilson
McMaster University
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 402 3 L47-L54Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
Infrastructure
Onsala Space Observatory
DOI
10.1051/0004-6361:20030339