Mapping Spiral Structure on the far side of the Milky Way
Abstract
Little is known about the portion of the Milky Way lying beyond the Galactic center at distances of more than 9 kilo-parsec from the Sun. These regions are opaque at optical wavelengths due to absorption by interstellar dust, and distances are very large and hard to measure. We report a direct trigonometric parallax distance of 20.4_{-2.2}^{+2.8} kilo-parsec obtained with the Very Long Baseline Array to a water maser source in a region of active star formation. These measurements allow us to shed light on Galactic spiral structure by locating the Scutum-Centaurus spiral arm as it passes through the far side of the Milky Way, and to validate a kinematic method for determining distances in this region based on transverse motions.
Keywords
Cite
@article{arxiv.1710.06489,
title = {Mapping Spiral Structure on the far side of the Milky Way},
author = {Alberto Sanna and Mark J. Reid and Thomas M. Dame and Karl M. Menten and Andreas Brunthaler},
journal= {arXiv preprint arXiv:1710.06489},
year = {2017}
}
Comments
21 pages, 5 figures, 4 tables, published in Science, October 13 issue