The HNCO ring in the Sgr B2 region

Authors

YC Minh
William M. Irvine, University of Massachusetts - AmherstFollow

Publication Date

2006

Journal or Book Title

NEW ASTRONOMY

Abstract

The large-scale structure associated with the 2′N HNCO peak in Sgr B2 [Minh, Y.C., Haikala, L., Hjalmarson, Å., Irvine, W.M., 1998. ApJ 498, 261 (Paper I)] has been investigated. A ring-like morphology of the HNCO emission has been found; this structure may be colliding with the Principal Cloud of Sgr B2. This “HNCO Ring” appears to be centered at (l,b) = (0.7°,−0.07°), with a radius of 5 pc and a total mass of 1.0 × 10⁵ to 1.6 × 10⁶ M. The expansion velocity of the Ring is estimated to be 30–40 km s⁻¹, which gives an expansion time scale of 1.5 × 10⁵ year. The morphology suggests that collision between the Ring and the Principal Cloud may be triggering the massive star formation in the Sgr B2 cloud sequentially, with the latest star formation taking place at the 2′N position. The chemistry related to HNCO is not certain yet, but if it forms mainly via reaction with the evaporated OCN⁻ from icy grain mantles, the observed enhancement of the HNCO abundance can be understood as resulting from shocks associated with the collision between the Principal Cloud and the expanding HNCO Ring.

Comments

The published version is located at http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TJK-4JN7CR8-1&_user=1516330&_coverDate=07%2F31%2F2006&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1746110329&_rerunOrigin=google&_acct=C000053443&_version=1&_urlVersion=0&_userid=1516330&md5=55d39f3f33c42ba1fd1886db158ef6d2&searchtype=a

DOI

https://doi.org/10.1016/j.newast.2006.03.004

Pages

594-599

Volume

11

Issue

8

Recommended Citation

Minh, YC and Irvine, William M., "The HNCO ring in the Sgr B2 region" (2006). NEW ASTRONOMY. 184.
https://doi.org/10.1016/j.newast.2006.03.004