A Tale of Three: Magnetic Fields along the Orion Integral-shaped Filament as Revealed by the JCMT BISTRO Survey
Authors: Wu Jintai , Qiu Keping , Poidevin Frédérick , Bastien Pierre , Liu Junhao , Ching Tao-Chung , Bourke Tyler L. , Ward-Thompson Derek , Pattle Kate , Johnstone Doug , Koch Patrick M. , Arzoumanian Doris , Lee Chang Won , Fanciullo Lapo , Onaka Takashi , Hwang Jihye , Gouellec Valentin J. M. Le , Soam Archana , Tamura Motohide , Tahani Mehrnoosh , Eswaraiah Chakali , Li Hua-Bai , Berry David , Furuya Ray S. , Coudé Simon , Kwon Woojin , Lin Sheng-Jun , Wang Jia-Wei , Hasegawa Tetsuo , Lai Shih-Ping , Byun Do-Young , Chen Zhiwei , Chen Huei-Ru Vivien , Chen Wen Ping , Chen Mike , Cho Jungyeon , Choi Youngwoo , Choi Yunhee , Choi Minho , Chrysostomou Antonio , Chung Eun Jung , Dai Sophia , Francesco James Di , Diep Pham Ngoc , Doi Yasuo , Duan Hao-Yuan , Duan Yan , Eden David , 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 , Hayashi Saeko , Hoang Thiem , Houde Martin , Inoue Tsuyoshi , Inutsuka Shu-ichiro , Iwasaki Kazunari , Jeong Il-Gyo , Könyves Vera , Kang Ji-hyun , Kang Miju , Karoly Janik , Kataoka Akimasa , Kawabata Koji , Kim Shinyoung , Kim Mi-Ryang , Kim Kyoung Hee , Kim Kee-Tae , Kim Jongsoo , Kim Hyosung , Kim Gwanjeong , Kirchschlager Florian , Kirk Jason , Kobayashi Masato I.N. , Kusune Takayoshi , Kwon Jungmi , Lacaille Kevin , Law Chi-Yan , Lee Hyeseung , Lee Chin-Fei , Lee Sang-Sung , Lee Jeong-Eun , Li Dalei , Li Di , Li Guangxing , Liu Sheng-Yuan , Liu Tie , Liu Hong-Li , Lu Xing , Lyo A-Ran , Mairs Steve , Matsumura Masafumi , Matthews Brenda , Moriarty-Schieven Gerald , Nagata Tetsuya , Nakamura Fumitaka , Nakanishi Hiroyuki , Ngoc Nguyen Bich , Ohashi Nagayoshi , Park Geumsook , Parsons Harriet , Peretto Nicolas , Priestley Felix , Pyo Tae-Soo , Qian Lei , Rao Ramprasad , Rawlings Jonathan , Rawlings Mark , Retter Brendan , Richer John , Rigby Andrew , Sadavoy Sarah , Saito Hiro , Savini Giorgio , Seta Masumichi , Sharma Ekta , Shimajiri Yoshito , Shinnaga Hiroko , Tang Ya-Wen , Tang Xindi , Thuong Hoang Duc , Tomisaka Kohji , Tram Le Ngoc , Tsukamoto Yusuke , Viti Serena , Wang Hongchi , Whitworth Anthony , Xie Jinjin , Yang Meng-Zhe , Yen Hsi-Wei , Yoo Hyunju , Yuan Jinghua , Yun Hyeong-Sik , Zenko Tetsuya , Zhang Guoyin , Zhang Chuan-Peng , Zhang Yapeng , Zhou Jianjun , Zhu Lei , Looze Ilse de , André Philippe , Dowell C. Darren , Eyres Stewart , Falle Sam , Robitaille Jean-François , van Loo Sven 
Published: December 2024

Abstract
As part of the B-fields In Star-forming Region Observations survey, we present James Clerk Maxwell Telescope (JCMT) 850 μm polarimetric observations toward the Orion integral-shaped filament (ISF) that covers three portions known as OMC-1, OMC-2, and OMC-3. The magnetic field threading the ISF seen in the JCMT POL-2 map appears as a tale of three: pinched for OMC-1, twisted for OMC-2, and nearly uniform for OMC-3. A multiscale analysis shows that the magnetic field structure in OMC-3 is very consistent at all the scales, whereas the field structure in OMC-2 shows no correlation across different scales. In OMC-1, the field retains its mean orientation from large to small scales but shows some deviations at small scales. Histograms of relative orientations between the magnetic field and filaments reveal a bimodal distribution for OMC-1, a relatively random distribution for OMC-2, and a distribution with a predominant peak at 90∘ for OMC-3. Furthermore, the magnetic fields in OMC-1 and OMC-3 both appear to be aligned perpendicular to the fibers, which are denser structures within the filament, but the field in OMC-2 is aligned along with the fibers. All these suggest that gravity, turbulence, and magnetic field are each playing a leading role in OMC-1, 2, and 3, respectively. While OMC-2 and 3 have almost the same gas mass, density, and nonthermal velocity dispersion, there are on average younger and fewer young stellar objects in OMC-3, providing evidence that a stronger magnetic field will induce slower and less efficient star formation in molecular clouds.