Automatic Shell Detection in CGPS Data
Loading...
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
A numerical code aiming at the automatic detection of spherical expanding HI shells in radio data-cubes is presented. The following five shell parameters are allowed to vary within a specified range: angular radius, expansion velocity and three center coordinates (galactic coordinates l and b, and systemic radial velocity V). We discuss several factors which can reduce the sensitivity of the shell detection: the presence of noise (both instrumental and "structural"), the fragmentation and asphericity of the shell and the inhomogeneity of the background and/or foreground emission. The code is tested on four objects: two HII regions and two early B stars. We use HI data from the Canadian Galactic Plane Survey. In all four cases the evidence for an expanding HI shell is found.
6 pages, 4 figures; to appear in the proceedings of the conference "Interacting Winds from Massive Stars" (ASP Conference Series), eds. A. F. J. Moffat, and N. St-Louis
6 pages, 4 figures; to appear in the proceedings of the conference "Interacting Winds from Massive Stars" (ASP Conference Series), eds. A. F. J. Moffat, and N. St-Louis