Jan. 31 Tue 9:00-14:40 2022年度後期 総研大研究中間レポート発表会 Zoom/ 講義室
Jan. 31 Tue 10:00-11:30 太陽系小天体セミナー Zoom
Feb. 1 Wed 10:00-12:00 SOKENDAI Colloquium Zoom
Feb. 1 Wed 15:30-17:00 NAOJ Science Colloquium Zoom / Instrument Development Bldg. 3 (hybrid)
Feb. 3 Fri 11:00-12:00 ATCセミナー Zoomおよび大セミナー室
詳細は下記からご覧ください。
=============== Jan 31 Tue ===============
Campus：Mitaka
Seminar：2022年度後期 総研大研究中間レポート発表会
(SOKENDAI Progress Report Defense in the second semester, AY2022)
定例・臨時の別：臨時
日時：2023年1月31日（火） 9:00～14:40
場所：Zoomおよび講義室
講演者：池田 遼太（9:00～）(Ryota Ikeda)
所属：総研大 天文科学専攻 (the Department of Astronomical Science, SOKENDAI)
タイトル：High − resolution ALMA study of structure and gas kinematics of cluster galaxies at z =1.46
講演者：西垣 萌香（9:50～）(Moka Nishigaki)
所属：総研大 天文科学専攻 (the Department of Astronomical Science, SOKENDAI)
タイトル：Early Galaxy Formation Near and Far Probed with SDSS and JWST Data
講演者：吉田 有宏(10:50～)(Tomohiro Yoshida)
所属：総研大 天文科学専攻 (the Department of Astronomical Science, SOKENDAI)
タイトル：Observational Constraints on the Physical and Chemical Structures of Gas in Protoplanetary Disks with ALMA: A Case Study of the TW Hya Disk
講演者：越坂 紫織(13:00～)(Shiori Koshisaka)
所属：総研大 天文科学専攻 (the Department of Astronomical Science, SOKENDAI)
タイトル：Subaru/SCExAO の高速偏光差分撮像法による若い星周りの円盤の詳細観測
講演者：石神 瞬(13:50～)(Shun Ishigami)
所属：総研大 天文科学専攻 (the Department of Astronomical Science, SOKENDAI)
タイトル：Study of Heating Distributions along Coronal Loops Using Emission Line Spectroscopy and Bayesian Analysis
世話人の連絡先
名前：大学院係 松田
=============== Jan 31 Tue ===============
キャンパス：三鷹
セミナー名：太陽系小天体セミナー
定例・臨時の別：定例
日時：1月31日（火曜日）10時00分～11時30分
場所：Zoom
講演者：土屋智恵
世話人の連絡先
名前：渡部潤一
備考：テレビ会議またはスカイプによる参加も可
=============== Feb 1 Wed ===============
Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：February 1, 2023 10:00-12:00
Place：Zoom
Speaker : Taku Nishiumi
Affiliation: SOKENDAI 5th year (D3) (Supervisor: Norio Narita, Yasunori Hori, Hideyuki Izumiura, Wako Aoki)
Title: TBA
Speaker: Suzuka Nakano
Affiliation: SOKENDAI 4th year (D2) (Supervisor: Koichiro Nakanishi, Takashi Sekii, Masayuki Tanaka)
Title: TBA
Speaker: Takaho Masai
Affiliation: SOKENDAI 4th year (D2) (Supervisor: Alvaro Gonzalez, Yoshinori Uzawa, Takafumi Kojima)
Title: Optical Analysis of Current ALMA Band 8 Receiver Tertiary Optics
Facilitator
Name：Matsuda, Graduate Student Affairs Unit
=============== Feb 1 Wed ===============
Campus：Mitaka
Seminar：NAOJ Science Colloquium
Regularly Scheduled/Sporadic：Every Wednesday
Date and time：2023 Feb. 1, 15:30-17:00
Place：Zoom / Instrument Development Bldg. 3 (hybrid)
Speaker：Tomohito Yoshida
Affiliation：NAOJ (M2)
Title：Observational Constraints on the Dust Albedo Spectrum in a Protoplanetary Disk
Abstract：Planets and planetary cores are formed by the coagulation of dust grains in a protoplanetary disk. Therefore, it is crucial to constrain the dust composition. Such dust grains in the disk midplane are observed at mm wavelengths. However, it is challenging to observationally constrain the composition directly because the mm-wavelength continuum emission of the dust does not show features as seen in infrared wavelengths. Meanwhile, recent observations and theory show that scattering significantly affects the emission even in the mm-wavelengths when the grain size is large. Since the scattering albedo as a function of wavelength (“albedo spectrum”) depends on the dust composition and grain size distributions, the constraints on the albedo can provide a hint on the nature of the dust. However, observational constraints on the albedo have been also difficult due to its degeneracy with temperature. In this talk, we propose to use the pressure broadened CO line wings, which are optically thin and trace the deepest region of the disk, as a thermometer of the disk midplane. We apply the method to ALMA archival observations of CO J=2-1 and 3-2 lines in the inner region of the TW Hya disk, and derive the mm-wavelength albedo spectrum for the first time by combining observations of other bands. We also discuss the constraints on the dust properties.
Speaker：Kousuke Ishihara
Affiliation：NAOJ (D1)
Title：Observational research of fragmentation process in nearby star-forming regions
Abstract：In the star formation process, molecular clouds hierarchically form dense structures by collapsing and fragmentation, then eventually leading to protostars. The scale at which fragmentation occurs is considered to contribute to the formation of stellar systems such as clusters and multiples. The most basic case is thermal Jeans fragmentation, which is determined by the balance between self-gravity and the pressure gradient due to thermal motion, and the expected characteristic fragmentation scale is called thermal Jeans length. Comparing with the core separation distribution and Jeans length provides a clue to the fragmentation process from clumps to cores. We have analyzed ALMA data (spatial resolution: ∼ 1000 au at 3 kpc) for 30 high-mass star-forming regions. As a result, we found a characteristic peak at ∼ 6000 au, which is comparable to the Jeans length. We have also confirmed that the result is robust even if considering observational biases due to differences in spatial resolution and mass sensitivity. In this talk, I introduce preliminary results of a similar analysis applied to dense cores in nearby star-forming regions. I obtained separation distribution by applying a Minimum Spanning Tree to the core coordinates in core catalogs obtained from the Herschel Gould Belt Survey. The results show a variety of distribution shapes with peaks at >10000 au in each region. The peak separation was found to be about 0.1 times the Jeans length in all regions. This may indicate that dynamical processes such as cloud-scale gravitational instability are important in the core formation process.
Facilitator
Name：Akimasa Kataoka
Comment：English
=============== Feb 3 Fri ===============
キャンパス：三鷹
セミナー名：ATCセミナー
定例・臨時の別：臨時
日時：2月3日（金曜日）11時00分～12時00分
場所：大セミナー室 + Zoom
講演者： 美濃和 陽典 氏
所属：国立天文台ハワイ観測所
タイトル：ULTIMATE-Subaru: すばる望遠鏡広視野補償光学（GLAO）の開発
Abstract：
ULTIMATE-Subaruはすばる望遠鏡の次期大型装置計画であり、HSC/PFSによる可視光域での広視野探査機能を近赤外線へと拡張する。ULTIMATE-Subaruでは、広視野補償光学（Ground Layer Adaptive Optics: GLAO)の技術を導入することで、近赤外線波長域において、これまでにない広視野かつ高感度のサーベイ観測を、ハッブル宇宙望遠鏡に匹敵する高解像度で実現する。GLAOでは、地表に近い大気層の揺らぎだけを測定し補正することで、広い視野に渡って均一な大気揺らぎ補正を行う。これにより、直径20分角に渡り波長2.2μmにおいて0.2秒角の星像が得られると期待されている。GLAOは、その広視野のために、従来の補償光学のような瞳面をリレーする光学系を取ることができず、望遠鏡の瞳面に相当する副鏡部を可変形鏡化する必要がある。そのため、GLAOでは望遠鏡全体を補償光学化する必要がある。GLAOを構成する主要サブシステムは、要となる可変形副鏡の他、波面を測定するための８個の波面センサー、波面参照のための４つのレーザーガイド星生成システム、リアルタイム制御系からなる。GLAOの開発は、ハワイ観測所、オーストラリア国立大学、東北大学の協力により進められており、2022年11月にはPreliminary Design Review (PDR）が完了し、現在詳細設計のフェーズに入っている。本講演では、GLAOの計画、設計、及びプロトタイプ試験の状況を紹介し、今後の開発計画について議論する。
世話人の連絡先
名前：永井 誠
備考：日本語での講演