Water Masers in W49 North and Sagittarius B2
| dc.creator | McGrath, E. J. | |
| dc.creator | Goss, W. M. | |
| dc.creator | De Pree, C. G. | |
| dc.date | 2004-07-19 | |
| dc.date.accessioned | 2026-07-07T11:08:20Z | |
| dc.date.available | 2026-07-07T11:08:20Z | |
| dc.description | Using the Very Large Array (VLA) of the National Radio Astronomy Observatory in the A and B configurations, we have obtained simultaneous high resolution observations of both the 22 GHz water maser lines as well as the 22 GHz continuum for the H II regions W49N and Sagittarius B2. The angular resolution of both observations is ~0.1", which at the distance of W49N (11.4 kpc; Gwinn, Moran, & Reid 1992) and Sgr B2 (8.5 kpc) corresponds to a physical size of <1000 AU in both sources. The velocity coverage for W49N is +/- 435 km/s; positions for 316 water maser components were obtained. The velocity coverage for Sgr B2 is -40 to +120 km/s; positions for 68 maser components were determined in Sgr B2 Main, 79 in Sgr B2 North, 14 in Sgr B2 Mid-North, and 17 in Sgr B2 South, for a total of 178 water maser positions in Sgr B2. The cross calibration scheme of Reid & Menten (1990, 1997) was used. Using this procedure, high dynamic range continuum images were obtained with accurate registration (rms ~0.01") of the continuum and maser positions. A detailed comparison between H II components and maser positions for both Sgr B2 and W49N is presented. In Sgr B2 Main, the water masers are predominantly located at the outside edge of the high-frequency continuum, lending support to the proposal that entrainment by stellar winds may play an important role in water maser emission. | |
| dc.description | 37 pages, including 6 figures and 6 tables. Accepted for publication in ApJS (Nov. 2004, v155). Data tables 2 - 6 are available in electronic format along with full resolution figures upon request (mcgrath@ifa.hawaii.edu) | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0407410 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0407410 | |
| dc.identifier | Astrophys.J.Suppl.155:577-593,2004 | |
| dc.identifier | doi:10.1086/424486 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/190098 | |
| dc.subject | Astrophysics | |
| dc.title | Water Masers in W49 North and Sagittarius B2 | |
| dc.type | text |