2024 : 12 : 27
Mohsen Nejad-Asghar

Mohsen Nejad-Asghar

Academic rank: Associate Professor
ORCID:
Education: PhD.
ScopusId:
HIndex:
Faculty: Science
Address:
Phone: 09355892196

Research

Title
MAGNETIC BRAKING OF THE ROTATION OF MOLECULAR CLOUD CORES, REVISITED
Type
Presentation
Keywords
Magnetic fields – Molecular cloud – Numerical method
Year
2024
Researchers Abbass Ebrahimi ، Mohsen Nejad-Asghar

Abstract

The phenomenon of magnetic braking is one of the significant physical effects of the magnetic field in rotating molecular clouds. Here, we revisit the work of Nakano (1989). In addition to receiving his results, the magnetic braking of a rotating molecular cloud core is investigated. We consider the density profile of the surrounding medium, in which the torsional Alfvén waves propagate, as power low. Regarding the presence of some dense regions around the molecular cloud cores, a Gaussian function is added to the density profile to represent these condensations in the surrounding medium. The numerical method is used in the Laplace space to ascertain the dependency of the angular velocity of the core to the time. Moreover, the presence of condensation does not have a significant effect on the magnetic braking. Also, the results show that the magnetic braking being stronger with increasing density ratio. This increasing indicates that the magnetic field is more firmly bonded to the bulk materials. This effect strengthens the magnetic tension force and slows down the core faster that indicates the importance of the magnetic braking. The results show that increasing density slope and/or decreasing density ratio are somewhat effective in weakening the magnetic braking and resolving its catastrophic effect.