Magnetic fields towards Ophiuchus-B derived from SCUBA-2 polarization measurements
Abstract
We present the results of dust emission polarization measurements of Ophiuchus-B (Oph-B) carried out using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera with its associated polarimeter (POL-2) on the James Clerk Maxwell Telescope (JCMT) in Hawaii. This work is part of the B-fields In Star-forming Region Observations (BISTRO) survey initiated to understand the role of magnetic fields in star formation for nearby star-forming molecular clouds. We present a first look at the geometry and strength of magnetic fields in Oph-B. The field geometry is traced over 0.2 pc, with clear detection of both of the sub-clumps of Oph-B. The field pattern appears significantly disordered in sub-clump Oph-B1. The field geometry in Oph-B2 is more ordered, with a tendency to be along the major axis of the clump, parallel to the filamentary structure within which it lies. The degree of polarization decreases systematically towards the dense core material in the two sub-clumps. The field lines in the lower density material along the periphery are smoothly joined to the large scale magnetic fields probed by NIR polarization observations. We estimated a magnetic field strength of 630410 G in the Oph-B2 sub-clump using a Davis-Chandeasekhar-Fermi analysis. With this magnetic field strength, we find a mass-to-flux ratio = 1.61.1, which suggests that the Oph-B2 clump is slightly magnetically supercritical.
Keywords
Cite
@article{arxiv.1805.06131,
title = {Magnetic fields towards Ophiuchus-B derived from SCUBA-2 polarization measurements},
author = {Archana Soam and Kate Pattle and Derek Ward-Thompson and Chang Won Lee and Sarah Sadavoy and Patrick M. Koch and Gwanjeong Kim and Jungmi Kwon and Woojin Kwon and Doris Arzoumanian and David Berry and Thiem Hoang and Motohide Tamura and Sang-Sung Lee and Tie Liu and Kee-Tae Kim and Doug Johnstone and Fumitaka Nakamura and A-Ran Lyo and Takashi Onaka and Jongsoo Kim and Ray S. Furuya and Tetsuo Hasegawa and Shih-Ping Lai and Pierre Bastien and Eun Jung Chung and Shinyoung Kim and Harriet Parsons and Mark Rawlings and Steve Mairs and Sarah F. Graves and J. -F. Robitaille and Hong-Li Liu and Anthony P. Whitworth and Chakali Eswaraiah and Ramprasad Rao and Hyunju Yoo and Martin Houde and Ji-hyun Kang and Yasuo Doi and Minho Choi and Miju Kang and Simon Coude and Hua-bai Li and Masafumi Matsumura and Brenda C. Matthews and Andy Pon and James Di Francesco and Saeko S. Hayashi and Koji S. Kawabata and Shu-ichiro Inutsuka and Keping Qiu and Erica Franzmann and Per Friberg and Jane S. Greaves and Jason M. Kirk and Di Li and Hiroko Shinnaga and Sven van Loo and Yusuke Aso and Do-Young Byun and Huei-Ru Chen and Mike C. -Y. Chen and Wen Ping Chen and Tao-Chung Ching and Jungyeon Cho and Antonio Chrysostomou and Emily Drabek-Maunder and Stewart P. S. Eyres and Jason Fiege and Rachel K. Friesen and Gary Fuller and Tim Gledhill and Matt J. Griffin and Qilao Gu and Jennifer Hatchell and Wayne Holland and Tsuyoshi Inoue and Kazunari Iwasaki and Il-Gyo Jeong and Sung-ju Kang and Francisca Kemper and Kyoung Hee Kim and Mi-Ryang Kim and Kevin M. Lacaille and Jeong-Eun Lee and Dalei Li and Junhao Liu and Sheng-Yuan Liu and Gerald H. Moriarty-Schieven and Hiroyuki Nakanishi and Nagayoshi Ohashi and Nicolas Peretto and Tae-Soo Pyo and Lei Qian and Brendan Retter and John Richer and Andrew Rigby and Giorgio Savini and Anna M. M. Scaife and Ya-Wen Tang and Kohji Tomisaka and Hongchi Wang and Jia-Wei Wang and Hsi-Wei Yen and Jinghua Yuan and Chuan-Peng Zhang and Guoyin Zhang and Jianjun Zhou and Lei Zhu and Philippe Andre and C. Darren Dowell and Sam Falle and Yusuke Tsukamoto and Yoshihiro Kanamori and Akimasa Kataoka and Masato I. N. Kobayashi and Tetsuya Nagata and Hiro Saito and Masumichi Seta and Jihye Hwang and Ilseung Han and Hyeseung Lee and Tetsuya Zenko},
journal= {arXiv preprint arXiv:1805.06131},
year = {2018}
}
Comments
17 pages, 10 figures, Accepted for publication in ApJ