TY - JOUR
T1 - The JCMT BISTRO Survey
T2 - The Magnetic Field In The Starless Core $ρ$ Ophiuchus C
AU - BISTRO
AU - Liu, Junhao
AU - Qiu, Keping
AU - Berry, David
AU - Francesco, James Di
AU - Bastien, Pierre
AU - Koch, Patrick M.
AU - Furuya, Ray S.
AU - Kim, Kee-Tae
AU - Coudé, Simon
AU - Lee, Chang Won
AU - Soam, Archana
AU - Eswaraiah, Chakali
AU - Li, Di
AU - Hwang, Jihye
AU - Lyo, A-Ran
AU - Pattle, Kate
AU - Hasegawa, Tetsuo
AU - Kwon, Woojin
AU - Lai, Shih-Ping
AU - Ward-Thompson, Derek
AU - Ching, Tao-Chung
AU - Chen, Zhiwei
AU - Gu, Qilao
AU - Li, Dalei
AU - Li, Hua-bai
AU - Liu, Hong-Li
AU - Qian, Lei
AU - Wang, Hongchi
AU - Yuan, Jinghua
AU - Zhang, Chuan-Peng
AU - Zhang, Guoyin
AU - Zhang, Ya-Peng
AU - Zhou, Jianjun
AU - Zhu, Lei
AU - André, Philippe
AU - Arzoumanian, Doris
AU - Aso, Yusuke
AU - Byun, Do-Young
AU - Chen, Michael Chun-Yuan
AU - Chen, Huei-Ru Vivien
AU - Chen, Wen Ping
AU - Cho, Jungyeon
AU - Choi, Minho
AU - Chrysostomou, Antonio
AU - Chung, Eun Jung
AU - Doi, Yasuo
AU - Drabek-Maunder, Emily
AU - Dowell, C. Darren
AU - Gledhill, Tim
AU - Parsons, Harriet
N1 - 22 pages, 12 figures
PY - 2019/5/22
Y1 - 2019/5/22
N2 - We report 850 μm dust polarization observations of a low-mass (∼12 M
o) starless core in the ρ Ophiuchus cloud, Ophiuchus C, made with the POL-2 instrument on the James Clerk Maxwell Telescope (JCMT) as part of the JCMT B-fields In STar-forming Region Observations survey. We detect an ordered magnetic field projected on the plane of the sky in the starless core. The magnetic field across the ∼0.1 pc core shows a predominant northeast-southwest orientation centering between ∼40° and ∼100°, indicating that the field in the core is well aligned with the magnetic field in lower-density regions of the cloud probed by near-infrared observations and also the cloud-scale magnetic field traced by Planck observations. The polarization percentage (P) decreases with increasing total intensity (I), with a power-law index of -1.03 ± 0.05. We estimate the plane-of-sky field strength (B
pos) using modified Davis-Chandrasekhar-Fermi methods based on structure function (SF), autocorrelation function (ACF), and unsharp masking (UM) analyses. We find that the estimates from the SF, ACF, and UM methods yield strengths of 103 ± 46 μG, 136 ± 69 μG, and 213 ± 115 μG, respectively. Our calculations suggest that the Ophiuchus C core is near magnetically critical or slightly magnetically supercritical (i.e., unstable to collapse). The total magnetic energy calculated from the SF method is comparable to the turbulent energy in Ophiuchus C, while the ACF method and the UM method only set upper limits for the total magnetic energy because of large uncertainties.
AB - We report 850 μm dust polarization observations of a low-mass (∼12 M
o) starless core in the ρ Ophiuchus cloud, Ophiuchus C, made with the POL-2 instrument on the James Clerk Maxwell Telescope (JCMT) as part of the JCMT B-fields In STar-forming Region Observations survey. We detect an ordered magnetic field projected on the plane of the sky in the starless core. The magnetic field across the ∼0.1 pc core shows a predominant northeast-southwest orientation centering between ∼40° and ∼100°, indicating that the field in the core is well aligned with the magnetic field in lower-density regions of the cloud probed by near-infrared observations and also the cloud-scale magnetic field traced by Planck observations. The polarization percentage (P) decreases with increasing total intensity (I), with a power-law index of -1.03 ± 0.05. We estimate the plane-of-sky field strength (B
pos) using modified Davis-Chandrasekhar-Fermi methods based on structure function (SF), autocorrelation function (ACF), and unsharp masking (UM) analyses. We find that the estimates from the SF, ACF, and UM methods yield strengths of 103 ± 46 μG, 136 ± 69 μG, and 213 ± 115 μG, respectively. Our calculations suggest that the Ophiuchus C core is near magnetically critical or slightly magnetically supercritical (i.e., unstable to collapse). The total magnetic energy calculated from the SF method is comparable to the turbulent energy in Ophiuchus C, while the ACF method and the UM method only set upper limits for the total magnetic energy because of large uncertainties.
KW - ISM: individual objects (Ophiuchus)
KW - magnetic fields
KW - polarization
KW - stars: formation
UR - http://www.scopus.com/inward/record.url?scp=85068692356&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ab0958
DO - 10.3847/1538-4357/ab0958
M3 - Article
SN - 0004-637X
VL - 877
JO - The Astrophysical Journal
JF - The Astrophysical Journal
IS - 1
M1 - 43
ER -