Date & Time: 2025/May/15 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.

Title: Magnetic Fields and the Formation of Multiple Systems in the High-mass Star Formation Regime

Speaker: Patricio Sanhueza (The University of Tokyo)

Abstract:

I will first introduce the MagMaR (Magnetic Fields in Massive Star-forming Regions) and the DIHCA (Digging into the Interior of Hot Cores with ALMA) surveys. Both ALMA surveys include 30 high-mass star-forming regions. MagMaR provides magnetic field information of star-forming cores at ~1000 au scales, while DIHCA reveals how these cores fragment at ~150 au scales. Each survey can independently answer many scientific questions, but, however, one of the ultimate goals is too evaluate how the magnetic field affects the formation of multiple systems. I will describe the first analysis combining both surveys. We have performed a full energy analysis including the magnetic field at core scales and have assessed what influences the multiplicity inside a massive core previously believed to be in the prestellar phase. In spite of the magnetic field having only a minor contribution to the total energy budget at core scales, it possibly plays a more important role at smaller scales by setting the binary properties. Considering energy ratios and a fragmentation criterion at the core scale, the binary system could have been formed by core fragmentation. The binary system properties (projected separation and mass ratio), however, are also consistent with radiation-magnetohydrodynamic simulations with super-Alfvenic or supersonic turbulence that form binaries by disk fragmentation.

The development of this project will require working closely with theorists to define key points that can help to assess the importance of the magnetic field in the formation of multiple systems, and if core or/and disk fragmentation are important.

他、会議報告、速報など、飛び入りも歓迎します。今回もしくは次回以降、話題提供できる方は世話人までメールしていただけましたら幸いです。 

Participants: 41,  Affiliations:14

Participants list:

ASIAA: PD Yuya Fukuhara

Ibaraki: P Munetake Momose, P Toru Turibe, D2 Ren Moriizumi, M2 Takumi Matsunaga, 

JAMSTEC: R Sota Arakawa

Kindai: Masayoshi Kiguchi

Kyushu: AP Doris Arzoumanian, PD Jihye Hwang, D3 Takashi Hayakawa, D2 Shingo Nozaki, D1 Itsuki Murakoso, M2 Reo Sakamoto

Kyushu Sangyo Univ.: A Kensuke Kakiuchi

Nagoya: P Shu-ichiro Inutsuka, AP Hiroshi Kobayashi, D3 Tomotaka Nishikawa, D2 Izumi Seno, D2 Riona Yamada, D1 Kenshin Onogawa, M2 Yuji Miko, M2 Shusuke Utsumi, M2 Kota Kobayashi, M2 Hayato Shimizu, M1 Kanaho Imata, M1 Yuki Tamaki, M1 Kohsei Nozaki

NAOJ: PD Yoshiaki Misugi

RIKEN: PD Yoshihide Yamato

Science Tokyo: A Kei Tanaka, PD Ryosuke Tominaga, D2 Ryota Yamamuro, RS Shintaro Taira

Shiga medical: AP Kazutaka Motoyama

Tohoku: PD Daisei Abe

UTokyo-Komaba: P Takeru Suzuki

UTokyo: AP Patricio Sanhueza, A Satoshi Ohashi, A Shota Notsu, PD Naoto Harada, D2 Yuto Komichi

次回：2025/May/27 17:00-

連絡世話人：冨永遼佑（東京科学大学） tominaga.r.aa[at]m.titech.ac.jp