Universität zu Köln

Mills, E. A. C., Ginsburg, A., Clements, A. R., Schilke, P., Sanchez-Monge, A., Menten, K. M., Butterfield, N., Goddi, C., Schmiedeke, A. and De Pree, C. G. (2018). Discovery of (NH3)-N-14 (2,2) Maser Emission in Sgr B2 Main. Astrophys. J. Lett., 869 (1). BRISTOL: IOP PUBLISHING LTD. ISSN 2041-8213

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Abstract

We report the discovery of the first (NH3)-N-14 (2,2) maser, seen in the Sgr B2 Main star-forming region near the center of the Milky Way, using data from the Very Large Array radio telescope. The maser is seen in both lower-resolution (3 '' or similar to 0.1 pc) data from 2012 and higher-resolution (0 ''.1 or similar to 1000 au) data from 2018. In the higher-resolution data NH3 (2,2) maser emission is detected toward five independent spots. The maser spots are not spatially or kinematically coincident with any other masers in this region, or with the peaks of the radio continuum emission from the numerous ultracompact and hypercompact H II regions in this area. While the (2,2) maser spots are spatially unresolved in our highest-resolution observations, they have unusually broad line widths of several kilometers per second, which suggests that each of these spots consists of multiple masers tracing unresolved velocity structure. No other NH3 lines observed in Sgr B2 Main are seen to be masers, which continues to challenge existing models of NH3 maser emission.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Mills, E. A. C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Ginsburg, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Clements, A. R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schilke, P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Sanchez-Monge, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Menten, K. M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Butterfield, N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Goddi, C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schmiedeke, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED De Pree, C. G. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-162240
DOI:	10.3847/2041-8213/aaf237
Journal or Publication Title:	Astrophys. J. Lett.
Volume:	869
Number:	1
Date:	2018
Publisher:	IOP PUBLISHING LTD
Place of Publication:	BRISTOL
ISSN:	2041-8213
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language HIGH-RESOLUTION OBSERVATIONS; AMMONIA MASER; SAGITTARIUS B2; MOLECULAR GAS; LINE; NH3; OUTFLOW; REGION; AU Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/16224