The JCMT BISTRO Survey: Unveiling the Magnetic Fields around Galactic Center
Abstract
We acquired 450 {\mu}m and 850 {\mu}m dust continuum polarization observations toward the inner region of the Central Molecular Zone (CMZ) as part of the B-Fields In Star-Forming Region Observations (BISTRO) survey using the POL-2 polarimeter on the James Clerk Maxwell Telescope. These observations encompassed three dense structures: the 20 km s{^{-1}} cloud (20MC), 50 km s{^{-1}} cloud (50MC), and circumnuclear disk (CND). Our aim is to investigate the magnetic field morphology and strength in the inner region of the CMZ using polarized dust continuum and the Davis-Chandrasekhar-Fermi method. The magnetic field morphology is highly ordered in all three dense regions. The plane-of-sky magnetic field strengths are {\sim}1 mG for the 20MC and the 50MC, and {\sim}2 mG for the CND. We compare the energy contributions of turbulence, gravity, and thermal motion with that of the magnetic field using the plasma {\beta}, mass-to-flux ratio, and Alfv\'en Mach number. The outcomes reveal the magnetic field stands out as the predominant factor within the inner region of the CMZ. The dominance of the magnetic field may explain the low star-forming rate in the CMZ. We further investigate the dust grain alignment efficiency by exploring the relationship between polarization fraction and total intensity. The results suggest that dust grains are well aligned with the magnetic fields.
Cite
@article{arxiv.2503.05198,
title = {The JCMT BISTRO Survey: Unveiling the Magnetic Fields around Galactic Center},
author = {Meng-Zhe Yang and Shih-Ping Lai and Janik Karoly and Kate Pattle and Xing Lu and David Eden and Sheng-Jun Lin and Frédérick Poidevin and Ekta Sharma and Jihye Hwang and Lapo Fanciullo and Mehrnoosh Tahani and Patrick M. Koch and Shu-ichiro Inutsuka and Valentin J. M. Le Gouellec and Hao-Yuan Duan and Jia-Wei Wang and Gary Fuller and Ray S. Furuya and Qilao Gu and Tetsuo Hasegawa and Guangxing Li and Junhao Liu and M. S. Akshaya and Bijas Najimudeen and Le Ngoc Tram and Derek Ward-Thompson and Doris Arzoumanian and James Di Francesco and Yasuo Doi and Thiem Hoang and Ji-hyun Kang and Jungmi Kwon and Woojin Kwon and Chang Won Lee and Tie Liu and Takashi Onaka and Sarah Sadavoy and Motohide Tamura and Pierre Bastien and David Berry and Simon Coudé and Keping Qiu},
journal= {arXiv preprint arXiv:2503.05198},
year = {2025}
}
Comments
Accepted for publication in ApJ. 31 pages, 21 figures (20 in main text, 1 in appendix), 1 appendix