Title:	Shock-heated NH3 in a molecular jet associated with a high-mass young star
Authors:	Zhang, Q. Hunter, T.R. Sridharan, T.K. Cesaroni, R.
Keywords:	ISM: H II REGIONS ISM: CLOUDS ISM: INDIVIDUAL: ALPHANUMERIC: IRAS 20126+4104, ISM: KINEMATICS AND DYNAMICS, MASERS STARS: FORMATION STARS: PRE-MAIN-SEQUENCE
Issue Date:	20-Dec-1999
Publisher:	The University of Chicago Press for the American Astronomical Society
Citation:	Astrophysical Journal Letters, 1999, Vol.527, pL117-L120
Abstract:	We present the discovery of shock-excited NH3 in a well-collimated jet associated with the extremely young high-mass star IRAS 20126+4104. The NH3 (3, 3) and (4, 4) emission is dominated by three clumps along the SiO jet. At the end of the jet, there exists strong and broad (+/-10 km s-1) NH3 (3, 3) emission. With typical brightness temperatures greater than 500 K, the overall emission indicates a weakly inverted population and appears in an arc, consistent with the excitation by bow shocks. There are two bright spots in the NH3 (3, 3) emission with brightness temperatures of approximately 2000 K. The narrow line width (1.5 km s-1 FWHM), the small sizes (<0.3"), and the unusually high brightness temperature of the features are indicative of maser emission. Our observations provide clear evidence that NH3 (3, 3) masers are excited in shock regions in molecular outflows.
URI:	http://hdl.handle.net/2289/1430
ISSN:	0004-637X 1538-4357(Online)
Alternative Location:	http://dx.doi.org/10.1086/312411
Copyright:	(1999) by the American Astronomical Society.
Appears in Collections:	Research Papers (A&A)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.