2019ApJ...871...98Z


Query : 2019ApJ...871...98Z

2019ApJ...871...98Z - Astrophys. J., 871, 98-98 (2019/January-3)

Anchoring magnetic fields in turbulent molecular clouds. II. From 0.1 to 0.01 pc.

ZHANG Y., GUO Z., WANG H.H. and LI H.-B.

Abstract (from CDS):

We compared the magnetic field directions inferred from polarimetry data obtained from 100 pc scale inter-cloud media (ICM) and from subparsec scale molecular cloud cores. The highly correlated result led us to conclude that cloud turbulence must be sub-Alfvenic. Here we extend the study with 0.01 pc cores observed by interferometers. The inferred field directions at this scale significantly deviate from that of the surrounding ICM. An obvious question to ask is whether this high-resolution result contradicts the sub-Alfvenic picture concluded earlier. We performed MHD simulations of a slightly super-critical (magnetic criticality = 2) clouds with Alfvenic Mach number MA = 0.63 (MA ≡ <σV/VA>, where σV and VA are, respectively, local 3D velocity dispersion and Alfven velocity; <...>means the average within the entire simulated volume; e.g., Burkhart et al. 2009), which can reproduce the Paper I results, and observed the development toward smaller scales. Interestingly, all subregions hosting cores with nH2 > 105/cc (the typical density observed by interferometers) possess MA = 2-3. Not too surprisingly, these slightly super-Alfvenic cores result in B-field orientation offsets comparable to the interferometer observations. The result suggests that gravity can concentrate (and maybe also contribute to, which requires further study to confirm) turbulent energy and create slightly super-Alfvenic cores out of sub-Alfvenic clouds. The results of our simulations also agree with the observed velocity-scale, mass-scale, and field-density relations.

Abstract Copyright: © 2019. The American Astronomical Society.

Journal keyword(s): galaxies: star formation - ISM: clouds - ISM: magnetic fields - polarization - turbulence

Simbad objects: 22

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Number of rows : 22
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 [JCC87] IRAS 2A Y*O 03 28 55.55 +31 14 36.7           ~ 436 3
2 V* V512 Per Or* 03 29 03.7578170808 +31 16 03.947525688           ~ 370 0
3 [JCC87] IRAS 4A Y*O 03 29 10.49 +31 13 30.8           ~ 680 1
4 [JCC87] IRAS 4 FIR 03 29 10.9 +31 13 26           ~ 475 0
5 NGC 1333 OpC 03 29 11 +31 18.6           ~ 1357 1
6 [JCC87] IRAS 4B Y*O 03 29 12.058 +31 13 02.05           ~ 587 0
7 [JCC87] IRAS 4B2 smm 03 29 12.8 +31 13 02           ~ 16 0
8 NAME OMC-1 MoC 05 35 14 -05 22.4           ~ 1121 2
9 NAME Orion-KL SFR 05 35 14.16 -05 22 21.5           ~ 2191 1
10 OMC 3 MoC 05 35 20.0 -05 01 00           ~ 254 1
11 HOPS 88 Y*O 05 35 22.4451 -05 01 14.123           ~ 58 1
12 HOPS 87 Y*O 05 35 23.500 -05 01 29.58           ~ 88 0
13 V* V2457 Ori Or* 05 35 26.97000 -05 09 54.4644         18.858 ~ 142 0
14 OMC 2 MoC 05 35 27 -05 10.1           ~ 433 1
15 2MASS J05352762-0509337 Y*O 05 35 27.622 -05 09 33.78           ~ 89 0
16 NAME Orion Molecular Cloud MoC 05 56 -01.8           ~ 1018 1
17 NGC 2264 OpC 06 40 52 +09 52.6           ~ 1716 0
18 [WZM2000] MMS 1 mm 06 41 17.7 +09 29 03           ~ 8 0
19 NAME VLA 1623-243 Y*O 16 26 26.42 -24 24 30.0           ~ 399 0
20 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3416 1
21 NAME NGC 6334 FIR V Cl* 17 19 57 -35 57.5           ~ 90 0
22 NAME NGC 6334 I(N) smm 17 20 54 -35 45.0           ~ 141 1

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2022.11.30-18:04:51

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