Details

Autor(en) / Beteiligte

• Nishiyama, Shogo
• Tamura, Motohide
• Hatano, Hirofumi
• Kanai, Saori
• Kurita, Mikio
• Sato, Shuji
• Matsunaga, Noriyuki
• Nagata, Tetsuya
• Nagayama, Takahiro
• Kandori, Ryo
• Nakajima, Yasushi
• Kusakabe, Nobuhiko
• Sato, Yaeko
• Hough, James H
• Sugitani, Koji
• Okuda, Haruyuki

Titel

Magnetic Field Configuration at the Galactic Center Investigated by Wide Field Near-Infrared Polarimetry

Ist Teil von

• The Astrophysical journal, 2009, Vol.690 (2), p.1648-1658

Ort / Verlag

Bristol: IOP Publishing

Erscheinungsjahr

2009

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We present a polarimetric map of a 20' X 20' area toward the Galactic center. The polarization of point sources has been measured in the J, H, and KS bands using the near-infrared polarimetric camera SIRPOL on the 1.4 m telescope IRSF. One percent or better accuracy of polarization degree is achieved for sources with J < 14.5, H < 13.5, and KS < 12.0. 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 distribution of the position angles shows a peak at ~20°, nearly parallel to the Galactic plane, suggesting a toroidal magnetic configuration. The derived direction of the magnetic field is in good agreement with that obtained from far-infrared/millimeter 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.