Letter to the Editor
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany e-mail: [schilke,sleurini,kmenten]@mpifr-bonn.mpg.de
2 Observatorio Astronómico Nacional, C/Alfonso XII, 3, 28014 Madrid, Spain e-mail: email@example.com
Corresponding author: P. Schilke, firstname.lastname@example.org
Accepted: 23 October 2003
We report the detection of the silicon nitride (SiN) –1, –3/2 transition toward SgrB2(M), in absorption. Although it has been seen in a circumstellar envelope before, this is the first time this molecule has been detected in interstellar space. We estimate a column density of cm-2, which is a factor of 20-50 lower than that of silicon monoxide (SiO) toward this source. It is likely that this molecule, like SiO and FeO, is created by gas-phase chemistry after refractory elements, previously locked up in grain cores, have been released by sputtering in shocks.
Key words: astrochemistry / line: identification / ISM: abundances / ISM: molecules / ISM: individual objects: SgrB2(M) / radio lines: ISM
© ESO, 2003