تقرير
Magnetic Field Configuration at the Galactic Center Investigated by Wide Field Near-Infrared Polarimetry
| العنوان: | Magnetic Field Configuration at the Galactic Center Investigated by Wide Field Near-Infrared Polarimetry |
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| المؤلفون: | 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 |
| المصدر: | Astrophys.J.690:1648-1658,2009 |
| سنة النشر: | 2008 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics |
| الوصف: | We present a polarimetric map of a 20'x20' 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 about 20 deg, 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/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. Comment: 14 pages, 11 figures, Accepted for publication in ApJ, For higher resolution, see http://www.kusastro.kyoto-u.ac.jp/~shogo/papers/08NishiyamaMagFGC.pdf |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/0004-637X/690/2/1648 |
| URL الوصول: | http://arxiv.org/abs/0809.3089 |
| رقم الأكسشن: | edsarx.0809.3089 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/0004-637X/690/2/1648 |
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