Odin observations of ammonia in the Sgr A +50 km s-1 cloud and circumnuclear disk
Artikel i vetenskaplig tidskrift, 2017

Context. The Odin satellite is now into its sixteenth year of operation, much surpassing its design life of two years. One of the sources which Odin has observed in great detail is the Sgr A complex in the centre of the Milky Way. Aims. To study the presence of NH3 in the Galactic centre and spiral arms. Methods. Recently, Odin has made complementary observations of the 572 GHz NH3 line towards the Sgr A +50 km s-1 cloud and circumnuclear disk (CND). Results. Significant NH3 emission has been observed in both the +50 km s-1 cloud and the CND. Clear NH3 absorption has also been detected in many of the spiral arm features along the line of sight from the Sun to the core of our Galaxy. Conclusions. The very large velocity width (80 km s-1) of the NH3 emission associated with the shock region in the southwestern part of the CND may suggest a formation/desorption scenario similar to that of gas-phase H2O in shocks/outflows.

ISM: individual objects: Sgr A

ISM: molecules

Galaxy: center

ISM: clouds


Aa. Sandqvist

Stockholm Observatory

Åke Hjalmarson

Chalmers, Rymd- och geovetenskap

U. Frisk

Omnisys Instruments AB

S. Lundin

OHB Sweden

L. Nordh

Stockholm Observatory

Michael Olberg

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

G. Olofsson

Stockholm Observatory

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 599 A135


Astronomi, astrofysik och kosmologi