The JCMT BISTRO Survey: An 850/450 μm Polarization Study of NGC 2071IR in Orion B
Authors: Lyo A-Ran , Kim Jongsoo , Sadavoy Sarah , Johnstone Doug , Berry David , Pattle Kate , Kwon Woojin , Bastien Pierre , Onaka Takashi , Di Francesco James , Kang Ji-Hyun , Furuya Ray , Hull Charles L. H. , Tamura Motohide , Koch Patrick M. , Ward-Thompson Derek , Hasegawa Tetsuo , Hoang Thiem , Arzoumanian Doris , Won Lee Chang , Lee Chin-Fei , Byun Do-Young , Kirchschlager Florian , Doi Yasuo , Kim Kee-Tae , Hwang Jihye , Diep Pham Ngoc , Fanciullo Lapo , Lee Sang-Sung , Park Geumsook , Yoo Hyunju , Chung Eun Jung , Whitworth Anthony , Mairs Steve , Soam Archana , Liu Tie , Tang Xindi , Coudé Simon , André Philippe , Bourke Tyler L. , Vivien Chen Huei-Ru , Chen Zhiwei , Ping Chen Wen , Chen Mike , Ching Tao-Chung , Cho Jungyeon , Choi Minho , Choi Yunhee , Chrysostomou Antonio , Dai Sophia , Dowell C. Darren , Duan Hao-Yuan , Duan Yan , Eden David , Eswaraiah Chakali , Eyres Stewart , Fiege Jason , Fissel Laura M. , Franzmann Erica , Friberg Per , Friesen Rachel , Fuller Gary , Gledhill Tim , Graves Sarah , Greaves Jane , Griffin Matt , Gu Qilao , Han Ilseung , Hatchell Jannifer , Hayashi Saeko , Houde Martin , Inoue Tsuyoshi , Inutsuka Shu-ichiro , Iwasaki Kazunari , Jeong Il-Gyo , Kang Miju , Kataoka Akimasa , Kawabata Koji , Kemper Francisca , Kim Gwanjeong , Kim Mi-Ryang , Kim Shinyoung , Kim Kyoung Hee , Kirk Jason , Kobayashi Masato I. N. , Könyves Vera , Kusune Takayoshi , Kwon Jungmi , Lacaille Kevin , Lai Shih-Ping , Law Chi-Yan , Lee Jeong-Eun , Lee Yong-Hee , Lee Hyeseung , Li Dalei , Li Di , Li Hua-Bai , Liu Hong-Li , Liu Junhao , Liu Sheng-Yuan , Lu Xing , Matsumura Masafumi , Matthews Brenda , Moriarty-Schieven Gerald , Nagata Tetsuya , Nakamura Fumitaka , Nakanishi Hiroyuki , Bich Ngoc Nguyen , Ohashi Nagayoshi , Parsons Harriet , Peretto Nicolas , Priestley Felix , Pyo Tae-soo , Qian Lei , Qiu Keping , Rao Ramprasad , Rawlings Jonathan , Rawlings Mark G. , Retter Brendan , Richer John , Rigby Andrew , Saito Hiro , Savini Giorgio , Scaife Anna , Seta Masumichi , Shimajiri Yoshito , Shinnaga Hiroko , Tahani Mehrnoosh , Tang Ya-Wen , Tomisaka Kohji , Tram Le Ngoc , Tsukamoto Yusuke , Viti Serena , Wang Jia-Wei , Wang Hongchi , Xie Jinjin , Yen Hsi-Wei , Yuan Jinghua , Yun Hyeong-Sik , Zenko Tetsuya , Zhang Guoyin , Zhang Chuan-Peng , Zhang Yapeng , Zhou Jianjun , Zhu Lei , de Looze Ilse , Dowell C. Darren , Falle Sam , Robitaille Jean-François , van Loo Sven 
Published: September 2021

Abstract
We present the results of simultaneous 450 μm and 850 μm polarization observations toward the massive star-forming region NGC 2071IR, a target of the BISTRO (B-fields in STar-forming Region Observations) Survey, using the POL-2 polarimeter and SCUBA-2 camera mounted on the James Clerk Maxwell Telescope. We find a pinched magnetic field morphology in the central dense core region, which could be due to a rotating toroidal disklike structure and a bipolar outflow originating from the central young stellar object IRS 3. Using the modified Davis–Chandrasekhar–Fermi method, we obtain a plane-of-sky magnetic field strength of 563 ± 421 μG in the central ∼0.12 pc region from 850 μm polarization data. The corresponding magnetic energy density of 2.04 × 10−8 erg cm−3 is comparable to the turbulent and gravitational energy densities in the region. We find that the magnetic field direction is very well aligned with the whole of the IRS 3 bipolar outflow structure. We find that the median value of polarization fractions is 3.0% at 450 μm in the central 3′ region, which is larger than the median value of 1.2% at 850 μm. The trend could be due to the better alignment of warmer dust in the strong radiation environment. We also find that polarization fractions decrease with intensity at both wavelengths, with slopes, determined by fitting a Rician noise model of 0.59 ± 0.03 at 450 μm and 0.36 ± 0.04 at 850 μm, respectively. We think that the shallow slope at 850 μm is due to grain alignment at the center being assisted by strong radiation from the central young stellar objects.