Near-Infrared Polarimetry toward the Galactic Center
Abstract
Near-infrared polarimetry of point sources reveals the presence of a toroidal magnetic field in the central 20' x 20' region of our Galaxy. Comparing the Stokes parameters between high extinction stars and relatively low extinction ones, we have obtained a polarization originating from magnetically aligned dust grains at the central region of our Galaxy of at most 1-2 kpc. The derived direction of the magnetic field is in good agreement with that obtained from far-infrared/submillimeter observations, which detect polarized thermal emission from dust in the molecular clouds at the Galactic center. Our results show that by subtracting foreground components, near-infrared polarimetry allows investigation of the magnetic field structure at the Galactic center. The distribution of the position angles shows a peak at around 20deg, nearly parallel to the direction of the Galactic plane, suggesting a toroidal magnetic configuration.
Cite
@article{arxiv.0809.4945,
title = {Near-Infrared Polarimetry toward the Galactic Center},
author = {Shogo Nishiyama and Motohide Tamura and Hirofumi Hatano and Saori Kanai and Mikio Kurita and Shuji Sato and Tetsuya Nagata},
journal= {arXiv preprint arXiv:0809.4945},
year = {2008}
}
Comments
5 pages, 2 figures; to be published in: Astronomical Polarimetry 2008: Science from Small to Large Telescopes, ASP Conference Series. For higher resolution, see http://www.kusastro.kyoto-u.ac.jp/~shogo/papers/ProcAstroPol08Nishiyama.pdf