作者
徐烨（南大天文系/上海台）、Mark Reid（哈佛-史密松森天体物理中心）、郑兴武（南大天文系）、Karl Menten（马普）
The Distance to the Perseus Spiral Arm in the Milky Way
Authors: Y. Xu (NJU, Cfa, Shao), M. J. Reid (CfA), X. W. Zheng (NJU), K. M. Menten (MPIfR)
Comments: 19 pages, 4 figures, Science Express December 8, 2005
We have measured the distance to the massive star-forming region W3OH in the Perseus spiral arm of the Milky Way to be 1.95 $\pm$ 0.04 kilo-parsecs ($5.86\times10^{16}$ km). This distance was determined by triangulation, with the Earth's orbit as one segment of a triangle, using the Very Long Baseline Array. This resolves a long-standing problem of a factor of two discrepancy between different techniques to determine distances. The reason for the discrepancy is that this portion of the Perseus arm has anomalous motions. The orientation of the anomalous motion agrees with spiral density-wave theory, but the magnitude is somewhat larger than most models predict.
http://www.arxiv.org/abs/astro-ph/0512223 |
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