July 19 Tue 13:30~14:10 SOKENDAI Progress Report Defence zoom
July 20 Wed 10:30~12:00 SOKENDAI Colloquium zoom
July 20 Wed 14:30~15:30 ALMA J Seminar zoom
July 20 Wed 15:30~17:00 NAOJ Science Colloquium zoom
July 22 Fri 13:30~15:00 Solar and Space Plasma Seminar zoom
July 22 Fri 16:00~17:00 談話会 NAOJ Seminar zoom/Large Seminar Room
詳細は以下をご覧下さい
7月19日(火)
Campus:Mitaka
Seminar:SOKENDAI Progress Report Defence
Regularly Scheduled/Sporadic:Sporadic
Date and time:July 19th, 2022 13:30-14:10
Place:zoom
Speaker: Abdurrahman Naufal
Title: Environmental effects on the morphology of star-forming galaxies at z ∼ 2
Examiner: Masami Ouchi, Daisuke Iono, Masatoshi Imanishi
Facilitator
-Name:Matsuda, Graduate Student Affairs Unit
7月20日(水)
Campus:Mitaka
Seminar:SOKENDAI Colloquium
Regularly Scheduled/Sporadic:Regular
Date and time:July 20th, 2022 10:30-12:00
Place:zoom
Speaker 1: Kuria Watanabe
Affiliation: SOKENDAI 1st year (M1) (Supervisor: Masami Ouchi, Nozomu Tominaga, Masato Onodera)
Title: Uncovering the Origin of Very High Fe/O in Young Star Forming Galaxies
Speaker 2: Masato Sato
Affiliation: SOKENDAI 3rd year (M1) (Supervisor: Nozomu Tominaga, Tomoya Takiwaki, Takashi Moriya)
Title: SN2018zd: a promising candidate of electron capture supernova & Progress of light curve modeling
Facilitator
-Name:Matsuda, Graduate Student Affairs Unit
7月20日(水)
Campus:Mitaka
Seminar:ALMA-J seminar
Regularly Scheduled/Sporadic:Every Wednesday
Date and Time:2022 July 20 14:30-15:30
Place:Zoom
Speaker:Blake Ledger
Affiliation:McMaster University
Title: Dense Molecular Gas in Extreme Galaxies: Gas Properties and CN/HCN Column Density Ratios
Abstract: The Atacama Large Millimeter Array (ALMA) is a next generation telescope with the ability to observe nearby galaxies with unprecedented angular resolution and sensitivity. ALMA gives us access to the densest molecular gas on detailed spatial scales, providing valuable insight into the physical and chemical processes that regulate star formation. I will present results from a multi-transition line study using both new and archival ALMA data of three lines each of CN and HCN in three unique extragalactic systems. These molecules have high critical densities, and their formation and destruction pathways depend on the astrochemical link between molecular gas properties and radiation field strengths. I explore if CN and HCN column density ratios can allow us to tease out the impact of UV and X-ray radiation on molecular gas chemistry, and whether a constant N_CN/N_HCN ratio may allow us to use CN as a dense gas tracer equivalent to HCN in future observations. Additionally, I will present the most recent results from a large sample survey of the CN/CO ratio in nearby U/LIRGs. This seminar will consist of three parts: an introduction about Canada and the institutions I have attended; my research work as an MSc and PhD student at McMaster University; and my research work this summer while visiting the National Astronomical Observatory of Japan.
Facilitator
Daisuke Iono, Andrea Silva
7月20日(水)
Campus:Mitaka
Seminar:NAOJ Science Colloquium
Regularly Scheduled/Sporadic:Every Wednesday
Date and time:2022 July 20, 15:30-17:00
Place:zoom / Instrument Development Bldg. 3 (hybrid)
Speaker:Takanori Kodama
Affiliation:University of Tokyo
Title:Climates of terrestrial exoplanets with 3D GCM
Abstract:Many exoplanets have been detected since 1995. Some of them are expected to be rocky planets with Earth-like bulk composition within the habitable zone, which is defined as the region around the central star where liquid water on the planetary surface remains stable for a long term. New space telescope observations are planned to reveal the characteristics of the atmosphere of exoplanets. In the next decade, such potential habitable exoplanets will be the primary targets for observation of life on exoplanets. Classically, the planetary atmosphere has been investigated with 1D radiative-convective equilibrium model. Recently, the climate for exoplanets in the habitable zone has been estimated with 3D general circulation models (GCMs) to capture the non-uniformity.
In this talk, I will review the habitability of terrestrial exoplanets from the viewpoint of 1D and 3D climate models. And I will show our recent studies where we focus on the distribution of water on the surface and in the atmosphere. We found that habitability is strongly depended on the surface environment. Finally, I will introduce an application with NICAM(Non-hydrostatic ICOsahedral Atmospheric Model), known as a global cloud resolved model, and will discuss the difference between a classical GCM and a global cloud resolved model.
Facilitator
-Name:Akimasa Kataoka
Comment:English
7月22日(金)
Campus: Mitaka
Seminar: Solar and Space Plasma Seminar
Regularly Scheduled/Sporadic: Scheduled
Date and time:22 July (金), 13:30-15:00
Place: Zoom
Speaker:白戸春日
Affiliation:京都大学
Title:SMART/SDDI およびDST による太陽大気における波動の伝播と磁場との関係の観測的研究
彩層・コロナ加熱問題における有力と考えられているメカニズムのひとつに、波動説がある。光球で励起された音波のうち、ある周波数(cutoff 周波数)より低周波のものは上層に伝播出来ない。しかし磁力線が傾いた領域では、そうでない領域よりもcutoff 周波数が低くなると考えられており、より低周波の波も上層に伝播出来る。このことを観測的に検証するためには、波の伝播と磁場の関係に着目することが肝要である。したがって本研究では、太陽全面分光撮像データを用いて静穏領域における波の振る舞いを、磁場との関係という観点で調査した。
使用したのは、京都大学飛騨天文台SMART/SDDIで得られた、いずれも12時間以上晴天が続いた2019年5月4日、2022年5月4日の太陽全面分光撮像データである。解析領域はdisc centerおよび赤道上の東のリム寄りの領域で、いずれも180Mm平方である。解析波長はHα線で、その時系列データから強度や速度などのパラメータを抽出した。そしてパワースペクトルや位相差を計算し、ネットワーク領域(NR)とインターネットワーク領域(INR)での結果を比較した。なお、2日分の解析を行ったのは、2021年8月にリオフィルターの温度安定性を向上させたためである。
その結果、まず、line centerの強度が強い場所ではその線幅も広くなっていた。これはCauzzi et al. 2009、Molnar et al. 2019の結果と一致しており、形成高度での温度を反映していると考えられる。次に、line centerのドップラー速度のパワーマップにおいて、3分周期ではdisc centerでもリム寄りの領域でもINRで強くなっていた。これはLites et al. 1993、Cauzzi et al. 2000などの結果と一致しており、彩層cavityの存在を示唆していると考えられる。一方、5分周期でも、同様にdisc centerでもリム寄りの領域でもINRで強くなっていた。これはLites et al. 1993、Cauzzi et al. 2000などの結果に矛盾している。さらに、コンティニウムでの強度とline centerでのドップラー速度の位相差スペクトルでは、リム寄りの領域ではdisc centerに比べてcutoff周波数が低くなっていることを示唆していると考えられる。これは、DePontieu et al. 2004、Jefferies et al. 2006で提唱されている通りで、傾いた磁力線を伝播してくる圧縮波のcutoff周波数が低下していることを示唆していると考えられる。なお、これらの結果はいずれの日でも共通していた。
Facilitator
-Name:大場崇義
Comment:日本語
7月15日(金)
Campus:Mitaka
Seminar:談話会 NAOJ Seminar
Regularly Scheduled/Sporadic:Every Friday
Date and time:2022 July 22, 16:00-17:00
Place:zoom / Large Seminar Room
Speaker:Lluís Galbany
Affiliation:Institute of Space Sciences (ICE-CSIC)
Title:A supernova in the borough: Integral field spectroscopy of SN Ia host galaxies
Abstract:Integral Field Spectroscopy (IFS) applied to supernova (SN) environmental studies have shown the potential of this technique to directly characterize the galactic environmental parameters at SN locations, compare them to those at different locations of the galaxy, and put constraints on progenitor stars for different SN types. Here, I will summarize past efforts of studying supernova environments with either global/local photometry/spectroscopy, and current efforts for improvement from the two largest SN host galaxy surveys with IFS: PISCO which was built from the selected sample of SN hosts from the CALIFA survey, and AMUSING, which has used more than 600h of VLT time with MUSE to compile a sample of SN host galaxies.
Facilitator
-Name:藤井 友香 / Fujii, Yuka