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Outflows Driven from a Magnetic Pseudodisk

delete2024-03-21
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OA
AI
S
Shantanu Basu *
M
Mahmoud Sharkawi
M
Masahiro N. Machida
DOI:10.3847/1538-4357/ad1bf3delete
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Abstract

Abstract

En 中文
Outflows play a pivotal role in star formation as one of its most visible markers and a means of transporting mass, momentum, and angular momentum from the infalling gas into the surrounding molecular cloud. Their wide reach (at least thousands of astrnomical units) is a contrast to typical disk sizes (similar to 10-100 au). We employ high-resolution three-dimensional nested-grid nonideal magnetohydrodynamic (MHD) simulations to study outflow properties in the Class 0 phase. We find that no disk wind is driven from the extended centrifugal disk that has weak magnetic coupling. The low-velocity winds emerge instead from the infalling magnetic pseudodisk. Much of the disk actually experiences an infall of matter rather than outflowing gas. Some of the pseudodisk wind (PD-wind) moves inward to regions above the disk and either falls onto the disk or proceeds upward. The upward flow gives the impression of a disk wind above a certain height even if the gas is originally emerging from the pseudodisk. The PD-wind has the strongest flow coming from a disk interaction zone that lies just outside the disk and is an interface between the inwardly advected magnetic field of the pseudodisk and the outwardly diffusing magnetic field of the disk. The low-velocity wind exhibits the features of a flow driven by the magnetic pressure gradient force in some regions and those of a magnetocentrifugal wind in other regions. We interpret the structure and dynamics of the outflow zone in terms of the basic physics of gravity, angular momentum, magnetic fields, and nonideal MHD.
Keywords:
GRAVITATIONAL COLLAPSE
PROTOSTELLAR OUTFLOWS
AMBIPOLAR DIFFUSION
ACCRETION DISKS
EVOLUTION
FLOWS
ROTATION
CLOUDS
CORES
FRAGMENTATION

Journal

Astrophysical Journal cover
Astrophysical Journal
IF:
5.4
Papers:
8.3W
Citations:
32.0W

Organization

W
western university (university of western ontario)
Scholars:
2.9W
Papers: 2.7W
Citations: 33