Date & Time: 2026/October/1 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:
Understanding how molecular cloud properties vary as a function of galaxy type and local galactic conditions provides crucial insights into star formation and galaxy evolution. To probe morphological quenching, the WISDOM (mm-Wave Interferometric Survey of Dark Object Masses) project expands spatially-resolved studies to early-type galaxies and bulges. Here, I present the results of ALMA CO(J=2-1) observations of the nearby lenticular galaxy NGC1574 at a spatial resolution of 10pc. The molecular gas disc is spatially compact, extending to a radius of only ~120pc, and appears remarkably smooth and symmetric even at this high resolution. Thus, ''giant'' molecular clouds are few in this galaxy. We identified 58 clouds within the molecular gas disc. The clouds exhibit strong internal velocity gradients (~0.03 - 1.14 km s^-1 pc^-1), suggesting that both these gradients and the observed cloud velocity dispersions, that are typically larger than those of Milky Way clouds, are influenced by galactic rotation. The median virial parameter is ~ 2.8, indicating that the clouds are unbound or only marginally bound. The observed cloud molecular gas mass surface densities are insufficient to resist shear, and the cloud radii exceed their tidal radii, indicating the clouds are likely to be disrupted and transient. Overall, these results suggest that strong shear prevents the formation of gravitationally bound clouds in NGC1574, resulting in a smooth molecular gas disc and molecular gas physical conditions that are unfavourable to star formation.
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:32, Affiliations:11
Aoyamagakuin U., A, Daisei Abe
ASIAA, PD, Yuya Fukuhara
Kindai Masayoshi Kiguchi
Kyushu D3 Ayumu Shoshi, D3 Shingo Nozaki
Nagoya P Shu-ichiro Inutsuka, AP Hiroshi Kobayashi, PD Shota Yokoyama, PD Katsushi Kondo, D3 Izumi Seno, D2 Kenshin Onogawa, D1 Shusuke Utsumi, M2 Kanaho Imata, M1 Kato Sota, M1 Kento Morita, M1 Masato Yamada, M1 Sota Maruyama
NDA A Kenji Kurosaki
RIKEN PD Miyu Kido
Science Tokyo PD Ryosuke Tominaga, D3 Ryota Yamamuro, B4 Taichi Mochida
Tohoku Univ. PD Ayu Konishi
Tokushima Univ. AP Ray Furuya
Utokyo P Takeru Suzuki, P Yuri Aikawa, PD Naoto Harada, A Shota Notsu, D3 Ren Matsusaka, D3 Yuto Komichi, D1 Maki Nagata, M2 Shiori Iwano
次回：2026/December/17 17:00-
連絡世話人：冨永遼佑（東京科学大学）tominaga.r.02d6[at]m.isct.ac.jp