W49 North与Sagittarius B2的水面星
摘要
我们使用国家射电望远镜局（NRAO）的Very Large Array（VLA）在A和B配置中，对W49N和Sagittarius B2的两个H II区域进行了同时高分辨率观测，观测了22 GHz水面星线以及22 GHz连续光。两种观测的角分辨率均为~0.1”，在W49N（距离11.4 kpc；Gwinn, Moran, & Reid 1992）和Sgr B2（距离8.5 kpc）处，对应物理尺寸均为<1000 AU。W49N的速度覆盖范围为±435 km/s，测得316个水面星成分的位置；Sgr B2的速度覆盖范围为-40至+120 km/s，测得Sgr B2 Main 68个、Sgr B2 North 79个、Sgr B2 Mid-North 14个、Sgr B2 South 17个水面星位置，共计178个水面星位置。采用Reid & Menten（1990, 1997）的交叉标定方案。通过该程序获取了动态范围高的连续光图像，连续光和面星位置精确对准（信噪比约0.01）。present both detailed comparison between H II components and maser positions for both Sgr B2 and W49N. 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.
引用
@article{arxiv.astro-ph/0407410,
title = {Water Masers in W49 North and Sagittarius B2},
author = {E. J. McGrath and W. M. Goss and C. G. De Pree},
journal= {arXiv preprint arXiv:astro-ph/0407410},
year = {2008}
}
备注
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 ([email protected])