УДК 53 Физика
УДК 520 Инструменты, приборы и методы астрономических наблюдений, измерений и анализа
УДК 521 Теоретическая астрономия. Небесная механика. Фундаментальная астрономия. Теория динамической и позиционной астрономии
УДК 523 Солнечная система
УДК 524 Звезды и звездные системы. Вселенная Солнце и Солнечная система
УДК 52-1 Метод изучения
УДК 52-6 Излучение и связанные с ним процессы
ГРНТИ 41.00 АСТРОНОМИЯ
ГРНТИ 29.35 Радиофизика. Физические основы электроники
ГРНТИ 29.31 Оптика
ГРНТИ 29.33 Лазерная физика
ГРНТИ 29.27 Физика плазмы
ГРНТИ 29.05 Физика элементарных частиц. Теория полей. Физика высоких энергий
ОКСО 03.06.01 Физика и астрономия
ОКСО 03.05.01 Астрономия
ОКСО 03.04.03 Радиофизика
ББК 2 ЕСТЕСТВЕННЫЕ НАУКИ
ББК 223 Физика
ТБК 614 Астрономия
ТБК 6135 Оптика
BISAC SCI004000 Astronomy
BISAC SCI005000 Physics / Astrophysics
We study numerically the gravitational fragmentation of a cylindrical molecular cloud with large-scale magnetic field. The simulations are performed with the help of the MHD code FLASH. We consider two cases: gravitational instability of the filament with initially deformed surface (model of Chandrasekhar and Fermi), and the instability of longitudinal compressible waves (model of Stodolkeiwicz). The simulations under typical parameters show that two types of the cores can be formed as a result of the fragmentation. Gravitational focusing leads to the formation of two massive clumps at the ends of filaments. Those cores move towards the cloud center with supersonic speeds. The instability of initial perturbations results in smaller evenly distributed cores inside the filament. The cores formed due to the instability of compressible waves have almost spherical shapes, while the cores resulted from the fragmentation of the filament with deformed surface are flattened. Typical sizes of the cores of 0.01–0.02 pc are in agreement with observations.
ISM: clouds, evolution, magnetic fields; magnetohydrodynamics (MHD); methods: numerical
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