TY - JOUR
T1 - The Effect of Misalignment between the Rotation Axis and Magnetic Field on the Circumstellar Disk
AU - Hirano, Shingo
AU - Tsukamoto, Yusuke
AU - Basu, Shantanu
AU - MacHida, Masahiro N.
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved..
PY - 2020/8/1
Y1 - 2020/8/1
N2 - The formation of circumstellar disks is investigated using three-dimensional resistive magnetohydrodynamic simulations in which the initial prestellar cloud has a misaligned rotation axis with respect to the magnetic field. We examine the effects of (i) the initial angle difference between the global magnetic field and the cloud rotation axis (θ 0) and (ii) the ratio of the thermal to gravitational energy (α 0). We study 16 models in total and calculate the cloud evolution until ∼5000 yr after protostar formation. Our simulation results indicate that an initial nonzero θ 0 (>0) promotes disk formation but tends to suppress outflow driving for models that are moderately gravitationally unstable, α 0 ≲ 1. In these models, a large-sized rotationally supported disk forms and a weak outflow appears, in contrast to a smaller disk and strong outflow in the aligned case (θ 0 = 0). Furthermore, we find that when the initial cloud is highly unstable with small α 0, the initial angle difference θ 0 does not significantly affect the disk formation and outflow driving.
AB - The formation of circumstellar disks is investigated using three-dimensional resistive magnetohydrodynamic simulations in which the initial prestellar cloud has a misaligned rotation axis with respect to the magnetic field. We examine the effects of (i) the initial angle difference between the global magnetic field and the cloud rotation axis (θ 0) and (ii) the ratio of the thermal to gravitational energy (α 0). We study 16 models in total and calculate the cloud evolution until ∼5000 yr after protostar formation. Our simulation results indicate that an initial nonzero θ 0 (>0) promotes disk formation but tends to suppress outflow driving for models that are moderately gravitationally unstable, α 0 ≲ 1. In these models, a large-sized rotationally supported disk forms and a weak outflow appears, in contrast to a smaller disk and strong outflow in the aligned case (θ 0 = 0). Furthermore, we find that when the initial cloud is highly unstable with small α 0, the initial angle difference θ 0 does not significantly affect the disk formation and outflow driving.
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U2 - 10.3847/1538-4357/ab9f9d
DO - 10.3847/1538-4357/ab9f9d
M3 - Article
AN - SCOPUS:85091696037
VL - 898
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 118
ER -