1. JCMT BISTRO Survey: Magnetic Fields within the Hub-filament Structure in IC 5146
- Author
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Jia-Wei Wang, Shih-Ping Lai, Chakali Eswaraiah, Kate Pattle, James Di Francesco, Doug Johnstone, Patrick M. Koch, Tie Liu, Motohide Tamura, Ray S. Furuya, Takashi Onaka, Derek Ward-Thompson, Archana Soam, Kee-Tae Kim, Chang Won Lee, Chin-Fei Lee, Steve Mairs, Doris Arzoumanian, Gwanjeong Kim, Thiem Hoang, Jihye Hwang, Sheng-Yuan Liu, David Berry, Pierre Bastien, Tetsuo Hasegawa, Woojin Kwon, Keping Qiu, Philippe André, Yusuke Aso, Do-Young Byun, Huei-Ru Chen, Michael C. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Simon Coudé, Yasuo Doi, C. Darren Dowell, Emily Drabek-Maunder, Hao-Yuan Duan, Stewart P. S. Eyres, Sam Falle, Lapo Fanciullo, Jason Fiege, Erica Franzmann, Per Friberg, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Sarah F. Graves, Jane S. Greaves, Matt J. Griffin, Qilao Gu, Ilseung Han, Jennifer Hatchell, Saeko S. Hayashi, Wayne Holland, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Yoshihiro Kanamori, Ji-hyun Kang, Miju Kang, Sung-ju Kang, Akimasa Kataoka, Koji S. Kawabata, Francisca Kemper, Jongsoo Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Jason M. Kirk, Masato I. N. Kobayashi, Vera Konyves, Jungmi Kwon, Kevin M. Lacaille, Hyeseung Lee, Jeong-Eun Lee, Sang-Sung Lee, Yong-Hee Lee, Dalei Li, Di Li, Hua-bai Li, Hong-Li Liu, Junhao Liu, A-Ran Lyo, Masafumi Matsumura, Brenda C. Matthews, Gerald H. Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Geumsook Park, Harriet Parsons, Enzo Pascale, Nicolas Peretto, Andy Pon, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Jean-François Robitaille, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Anna M. M. Scaife, Masumichi Seta, Hiroko Shinnaga, Ya-Wen Tang, Kohji Tomisaka, Yusuke Tsukamoto, Sven van Loo, Hongchi Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Chuan-Peng Zhang, Guoyin Zhang, Ya-Peng Zhang, Jianjun Zhou, and Lei Zhu
- Subjects
individual objects (IC 5146) [ISM] ,010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,ISM [radio continuum] ,Probability density function ,Astrophysics ,01 natural sciences ,law.invention ,Protein filament ,ISM: individual objects (IC 5146) ,ISM: magnetic fields ,ISM: structure ,polarization ,radio continuum: ISM ,stars: formation ,law ,0103 physical sciences ,010303 astronomy & astrophysics ,James Clerk Maxwell Telescope ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,formation [stars] ,Turbulence ,F510 ,Bolometer ,magnetic fields [ISM] ,Astronomy and Astrophysics ,Polarimeter ,Polarization (waves) ,Astrophysics - Astrophysics of Galaxies ,Magnetic field ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,structure [ISM] - Abstract
We present the 850 $\mu$m polarization observations toward the IC5146 filamentary cloud taken using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and its associated polarimeter (POL-2), mounted on the James Clerk Maxwell Telescope (JCMT), as part of the B-fields In STar forming Regions Observations (BISTRO). This work is aimed at revealing the magnetic field morphology within a core-scale ($\lesssim 1.0$ pc) hub-filament structure (HFS) located at the end of a parsec-scale filament. To investigate whether or not the observed polarization traces the magnetic field in the HFS, we analyze the dependence between the observed polarization fraction and total intensity using a Bayesian approach with the polarization fraction described by the Rice likelihood function, which can correctly describe the probability density function (PDF) of the observed polarization fraction for low signal-to-noise ratio (SNR) data. We find a power-law dependence between the polarization fraction and total intensity with an index of 0.56 in $A_V\sim$ 20--300 mag regions, suggesting that the dust grains in these dense regions can still be aligned with magnetic fields in the IC5146 regions. Our polarization maps reveal a curved magnetic field, possibly dragged by the contraction along the parsec-scale filament. We further obtain a magnetic field strength of 0.5$\pm$0.2 mG toward the central hub using the Davis-Chandrasekhar-Fermi method, corresponding to a mass-to-flux criticality of $\sim$ $1.3\pm0.4$ and an Alfv\'{e}nic Mach number of $, Comment: 24 pages, 15 figures, accepted for publication in ApJ
- Published
- 2019