June 20 Tue 10:20-16:30 博士後期課程中間報告会 Zoom / the large seminar room (hybrid)
june 21 Wed 10:30-12:00 SOKENDAI Colloquium Zoom / the large seminar room (hybrid)
June 21 Wed 14:30-15:30 ALMA-J seminar Zoom / ALMA building #102 (hybrid)
June 21 Wed 15:30-17:00 NAOJ Science Colloquium Zoom / the large seminar room (hybrid)
詳細は下記からご覧ください。
=============== June 20 Tue===============
キャンパス：三鷹
セミナー名：博士後期課程中間報告会
定例・臨時の別：臨時
日時： 6月20日（火曜日） 10時20分～16時30分
場所：大セミナー室およびZoom
発表者： 石原 昂将 （10:20～）
所属：総研大 天文科学専攻
タイトル：星形成領域における分裂過程の観測的研究
発表者：小上 樹 （11:10～）
所属：総研大 天文科学専攻
タイトル： すばる望遠鏡/Hyper Suprime-Camで探る局所銀河群銀河恒星ハローの構造と性質
発表者：佐藤 大仁 （13:00～）
所属：総研大 天文科学専攻
タイトル：理論・観測研究から迫る電子捕獲型超新星の特徴の解明
発表者：佐々木 俊輔 （13:50～）
所属：総研大 天文科学専攻
タイトル：Phenomenological turbulent effects of core-collapse supernovae Toward predicting progenitor dependence
発表者：多田 将太朗 （14:50～）
所属：総研大 天文科学専攻
タイトル：宇宙望遠鏡での精密測光・位置天文に向けた検出器の高精度較正手法の開発
発表者：土井 聖明 （15:40～）
所属：総研大 天文科学専攻
タイトル：原始惑星系円盤のALMA観測及びモデリングから解き明かすダスト成長過程
世話人の連絡先
-名前：大学院係 松田
=============== June 21 Wed===============
Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：June 21, 2023 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom
Speaker: Tomohiro Yoshida
Affiliation: SOKENDAI 3rd year (D1) (Supervisor: Hideko Nomura, Misato Fukagawa, Akimasa Kataoka)
Title: Observational Constraints on Dust Scattering Albedo in a Protoplanetary Disk
Speaker : Kiyoaki Doi
Affiliation: SOKENDAI 4th year (D2) (Supervisor: Akimasa Kataoka, Hideko Nomura, Misato Fukagawa)
Title: Constraints on the dust size distribution in the HD 163296 disk from the difference of the apparent dust ring width
between two ALMA Bands
Facilitator
-Name：Matsuda, Graduate Student Affairs Unit
=============== June 21 Wed===============
Campus：Mitaka
Seminar：ALMA-J seminar
Regularly Scheduled/Sporadic： Every Wednesday
Date and time： June 21th, 2023 (Wed), 14:30 – 15:30
Place： ALMA building #102 / Zoom (hybrid)
Speaker: Kana Morokuma-Matsui
Affiliation: NAOJ
Title: Star-formation quenching in galaxies in the Virgo and Fornax clusters
Abstract: Understanding how star formation is suppressed in galaxies is a crucial aspect of galaxy evolution research.
The cosmic star-formation rate density has a peak around z~1-2, and the last half of the universe is the history of
SF quenching in galaxies. In this talk, we present our findings on how the galaxy-cluster environment affects SF activity
in galaxies by observing molecular gas in cluster galaxies. We focus on the Virgo and Fornax clusters,
which are the two nearest galaxy clusters to us. Our results show that SF activity is low in cluster galaxies due
to the depletion of cold gas reservoirs rather than the decrease in star-formation efficiency.
Furthermore, we find that the gas in cluster galaxies is likely to be removed in a shorter timescale than
the typical gas depletion timescale of ~1-3 Gyr. We also discuss the similarities and differences between the two clusters.
Facilitator: Toshiki Saito, Andrea Silva
=============== June 21 Wed===============
Campus：Mitaka
Seminar：NAOJ Science Colloquium
Regularly Scheduled/Sporadic：Every Wednesday
Date and time：2023 June 21, 15:30-17:00
Place：zoom / the large seminar room (hybrid)
Speaker：Raiga Kashiwagi
Affiliation：NAOJ (D3)
Title：Simulation Study of Collisions Between Filamentary Molecular
Clouds Threaded by Lateral Magnetic Field and Subsequent Evolution
Abstract：
Most Stars are thought to be formed inside filamentary molecular
clouds. Recent observations have proposed that star formation may be
triggered through collisions between filamentary molecular clouds at
nearby star-forming regions(Duarte-Cabral et al. 2010; Nakamura et al.
2014). Furthermore, according to Kumar et al. (2020), all luminous
clumps with L > 10^4L⊙ and L > 10^5L⊙ at distances within 2 and 5 kpc
respectively are located at the intersections (referred to as “hubs”) of
filaments and this indicates the formation of massive stars
preferentially form at the hubs. Based on the above, filament collisions
are considered to be a universal and important phenomenon. Understanding
the filament collision process will reveal the initial conditions for
collision-induced star formation. Therefore, we have been working on
2D-MHD simulations of filament-filament collisions. In this colloquium,
we will report on the condition of radial instability of the merged
filament and its evolution. As the initial condition, we prepare two
identical infinite long filaments, threaded by lateral magnetic fields.
The filaments are in magnetohydrostatic equilibrium(Tomisaka 2014;
Kashiwagi & Tomisaka 2021). The two filaments collide head-on along the
magnetic field lines with relative velocities ranging from transonic to
supersonic. If the total line mass of the initial filaments exceeds the
critical line mass of the magnetized filament, the shocked region
collapses radially. On the other hand, for collisions where the total
line mass is below the critical value, the shocked region evolves into a
structure that closely resembles the magnetohydrostatic equilibrium
state. In addition, the results for the case where the collision
direction is perpendicular to the magnetic field lines are also briefly
introduced. Finally, we briefly introduce the preliminary results of the
Orthogonal collision which is reproduced by the 3D-MHD simulation.
Speaker：Shinichi Kinoshita
Affiliation：NAOJ (D3)
Title：Unveiling the Dynamics of Dense Cores in Cluster-Forming Clumps: A
3D MHD Simulation Study of Angular Momentum and Magnetic Field Properties
Abstract：
Almost all stars within the Milky Way form as members of clusters.
Dense cores, the direct progenitor of stars, are formed in the
cluster-forming clumps and eventually form star clusters. Therefore,
comprehending the effect of the clump environment on core properties is
important for understanding star formation and galaxy evolution.
We conducted isothermal MHD simulations with self-gravity to
investigate the properties of dense cores in cluster-forming clumps. Two
different setups were explored: a single rotating clump and colliding
clumps. We focused on determining the extent to which the rotation and
magnetic field of the parental clump are inherited by the formed dense
cores. Our statistical analysis revealed that the alignment between the
angular momentum of dense cores, Lcore, and the rotational axis of the
clump is influenced by the strength of turbulence and the simulation
setup. In single rotating clumps, we found that Lcore tends not to align
with the clump’s rotational axis unless the initial turbulence is weak.
In colliding clumps, however, this alignment does not occur, regardless
of the initial turbulence strength. Our analysis of colliding clumps
also revealed that the magnetic field globally bends along the
shock-compressed layer, and the mean magnetic field of dense cores,
Bcore aligns with it. Both in single rotating clumps and colliding
clumps, we found that the angle between Bcore and Lcore is generally
random, regardless of the clump properties.
Facilitator
-Name：Kanji Mori
-Comment：English