Date & Time: 2024/August/29 17:00-18:00, Venue: Zoom TV Conference System. This is an informal seminar on the formation of stars and planets. We welcome anyone interested in the subject.
Abstract: The angular momentum of molecular cloud cores plays a key role in the star formation process. However, the evolution of the angular momentum of molecular cloud cores formed in magnetized molecular filaments is still unclear. We perform three-dimensional magnetohydrodynamics simulations to reveal the effect of the magnetic field on the evolution of the angular momentum of molecular cloud cores formed through filament fragmentation. As a result, we find that the angular momentum decreases by 30% and 50% at the mass scale of 1 Msun in the case of weak and strong magnetic field, respectively. By analyzing the torques exerted on fluid elements at different mass scales, we identify the magnetic tension as the dominant process for angular momentum transfer for mass scales < 3 Msun for the strong magnetic field case. This critical mass scale can be understood semi-analytically as the time scale of magnetic braking. We show that the anisotropy of the angular momentum transfer due to the presence of strong magnetic field changes the resultant angular momentum of the core only by a factor of two. We also find that the distribution of the angle between the direction of the angular momentum and the magnetic field is random even just before the first core formation. Our results also indicate that the variety of the angular momentum of core inherited from the difference of the phase of the initial turbulent velocity field could contribute to the diversity in size and other properties of protoplanetary disks recently reported by observations.
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Participants: 41, Affiliations: 14
Participants list:
Ibaraki: P Toru Turibe, P Munetake Momose, D3 Ryuta Orihara, D3 Kensho Morii
ICRR: DAP Jiro Shimoda
JAMSTEC: PD Sota Arakawa
Kagoshima: D2 Miyu Kido
Kindai: Masayoshi Kiguchi
Kobe: 特命A Kenji Kurosaki
Nagoya: P Sei-ichiro Watanabe, P Shu-ichiro Inutsuka, AP Hiroshi Kobayashi, D3 Kanta Kitajima, D2 Ryushi Miyayama, D2 Tomotaka Nishikawa, D1 Riona Yamada, D1 Izumi Seno, M2 Kenshin Onogawa, M2 Wataru Takahashi, M1 Hayato Shimizu, M1 Kota Kobayashi, M1 Shusuke Utsumi, M1 Yuji Miko
NAOJ: PD Yuji Matsumoto, PD Yoshiaki Misugi
RIKEN: PD Yuki Okoda
Shiga Univ. of medical science: AP Motoyama
Tohoku: PD Daisei Abe, M1 Haruki Nabeta
Tokyo Tech: PD Ryosuke Tominaga, D3 Yuya Fukuhara, D1 Ryota Yamamuro, M1 Shogo Yamada
UTokyo-Komaba: Takato Tokuno
UTokyo: P Yuri Aikawa, PD Naoto Harada, D3 Kaho Morii, D3 Yoshihide Yamato, D2 Lily Ishizaki, D1 Yuto Komichi
次回：2024/Oct./10 17:00-
連絡世話人：冨永遼佑（東工大） tominaga.r.aa[at]m.titech.ac.jp