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arXiv · 2210.05937

The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2

Jihye Hwang·Jongsoo Kim·Kate Pattle·Chang Won Lee·Patrick M. Koch·Doug Johnstone·Kohji Tomisaka·Anthony Whitworth·Ray S. Furuya·Ji-hyun Kang·A-Ran Lyo·Eun Jung Chung·Doris Arzoumanian·Geumsook Park·Woojin Kwon·Shinyoung Kim·Motohide Tamura·Jungmi Kwon·Archana Soam·Ilseung Han·Thiem Hoang·Kyoung Hee Kim·Takashi Onaka·Eswaraiah Chakali·Derek Ward-Thompson·Hong-Li Liu·Xindi Tang·Wen Ping Chen·Masafumi Matsumura·Thuong Duc Hoang·Zhiwei Chen·Valentin J. M. Le Gouellec·Florian Kirchschlager·Fr ed erick Poidevin·Pierre Bastien·Keping Qiu·Tetsuo Hasegawa·Shih-Ping Lai·Do-Young Byun·Jungyeon Cho·Minho Choi·Youngwoo Choi·Yunhee Choi·Il-Gyo Jeong·Miju Kang·Hyosung Kim·Kee-tae Kim·Jeong-Eun Lee·Sang-sung Lee·Yong-Hee Lee·Hyeseung Lee·Mi-Ryang Kim·Hyunju Yoo·Hyeong-Sik Yun·Mike Chen·James Di Francesco·Jason Fiege·Laura M. Fissel·Erica Franzmann·Martin Houde·Kevin Lacaille·Brenda Matthews·Sarah Sadavoy·Gerald Moriarty-Schieven·Mehrnoosh Tahani·Tao-Chung Ching·Y. Sophia Dai·Yan Duan·Qilao Gu·Chi-Yan Law·Dalei Li·Di Li·Guangxing Li·Hua-bai Li·Tie Liu·Xing Lu·Lei Qian·Hongchi Wang·Jintai Wu·Jinjin Xie·Jinghua Yuan·Chuan-Peng Zhang·Guoyin Zhang·Yapeng Zhang·Jianjun Zhou·Lei Zhu·David Berry·Per Friberg·Sarah Graves·Junhao Liu·Steve Mairs·Harriet Parsons·Mark Rawlings·Yasuo Doi·Saeko Hayashi·Charles L. H. Hull·Tsuyoshi Inoue·Shu-ichiro Inutsuka·Kazunari Iwasaki·Akimasa Kataoka
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Abstract

We present and analyze observations of polarized dust emission at 850 $\mu$m towards the central 1 pc $\times$ 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the BISTRO (B-fields in Star-forming Region Observations) survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well-described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis-Chandrasekhar-Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from $Herschel$ data and the C$^{18}$O ($J$ = 3-2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 $\pm$ 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 $\pm$ 0.02. Additionally, the mean Alfv\'en Mach number is 0.35 $\pm$ 0.01. This suggests that in Mon R2, magnetic fields provide resistance against large-scale gravitational collapse, and magnetic pressure exceeds turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically sub-critical.

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Jihye Hwang, Jongsoo Kim, Kate Pattle, Chang Won Lee, Patrick M. Koch, Doug Johnstone, Kohji Tomisaka, Anthony Whitworth, Ray S. Furuya, Ji-hyun Kang, A-Ran Lyo, Eun Jung Chung, Doris Arzoumanian, Geumsook Park, Woojin Kwon, Shinyoung Kim, Motohide Tamura, Jungmi Kwon, Archana Soam, Ilseung Han, Thiem Hoang, Kyoung Hee Kim, Takashi Onaka, Eswaraiah Chakali, Derek Ward-Thompson, Hong-Li Liu, Xindi Tang, Wen Ping Chen, Masafumi Matsumura, Thuong Duc Hoang, Zhiwei Chen, Valentin J. M. Le Gouellec, Florian Kirchschlager, Fr ed erick Poidevin, Pierre Bastien, Keping Qiu, Tetsuo Hasegawa, Shih-Ping Lai, Do-Young Byun, Jungyeon Cho, Minho Choi, Youngwoo Choi, Yunhee Choi, Il-Gyo Jeong, Miju Kang, Hyosung Kim, Kee-tae Kim, Jeong-Eun Lee, Sang-sung Lee, Yong-Hee Lee, Hyeseung Lee, Mi-Ryang Kim, Hyunju Yoo, Hyeong-Sik Yun, Mike Chen, James Di Francesco, Jason Fiege, Laura M. Fissel, Erica Franzmann, Martin Houde, Kevin Lacaille, Brenda Matthews, Sarah Sadavoy, Gerald Moriarty-Schieven, Mehrnoosh Tahani, Tao-Chung Ching, Y. Sophia Dai, Yan Duan, Qilao Gu, Chi-Yan Law, Dalei Li, Di Li, Guangxing Li, Hua-bai Li, Tie Liu, Xing Lu, Lei Qian, Hongchi Wang, Jintai Wu, Jinjin Xie, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Yapeng Zhang, Jianjun Zhou, Lei Zhu, David Berry, Per Friberg, Sarah Graves, Junhao Liu, Steve Mairs, Harriet Parsons, Mark Rawlings, Yasuo Doi, Saeko Hayashi, Charles L. H. Hull, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Akimasa Kataoka. 2022-10-12. The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2. https://doi.org/10.3847/1538-4357/ac99e0

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