2017.9.25-10.1

        

9月25日(月)13:30~15:00   太陽天体プラズマセミナー          院生セミナー室                        
Sep 25 Mon            Solar and Space Plasma Seminar    Student Seminar Room, Subaru Bldg.

9月26日(火)13:30~15:00   太陽系小天体セミナー            南棟2階会議室
Sep 26 tue             Solar System Minor Body Seminar   Conference Room, South Bldg.2F

9月27日(水)10:30~12:00   総研大コロキウム               中央棟 講義室
Sep 27 Wed            SOKENDAI colloquium           Lecture Room

詳細は以下をご覧下さい。

9月25日(月)

Campus
Mitaka
Seminar
Solar and Space Plasma Seminar
Regularly Scheduled/Sporadic
Sporadic
Date and time
25 September (Mon), 13:30-15:00
Place
Student Seminar Room, Subaru Bldg.
Speaker
Antonia Savcheva
Affiliation
CfA/Harvard
Title
Solar Sigmoidal Active Regions: From Formation to Eruption
Abstract
The formation, evolution and eruption of solar active regions is a main theme in solar physics. Ultimately the goal is predicting when, where and how an eruption will occur, which will greatly aid space weather forecasting. S-shaped active regions (sigmoids) facilitate this line of research, since they provide conditions that are easier to disentangle and have a high probability for erupting as flares and/or coronal mass ejections. This talk explores the behaviour of solar sigmoids via both observational and magnetic field modeling studies. Data from the most modern space-based solar observatories are utilized in addition to data-constrained non-linear force-free field (NLFFF) models and MHD simulations to gain insight into the physical processes controlling the evolution and eruption of solar sigmoids. By means of a large comprehensive observational study we investigate the formation and evolution mechanism. Specifically, we show that flux cancellation is a major mechanism for flux rope formation and evolution. We demonstrate how X-ray observations are used to constrain the flux rope insertion method for building NLFFF models over the evolution of such sigmoids and make use of topological analysis to describe the magnetic field structure of the sigmoids. We show that when data-constrained models are used in sync with MHD simulations and observations we can arrive at a consistent picture of the scenario for CME onset, namely the positive feedback between reconnection at a generalized X-line and the torus instability. In addition, we show that topological analysis is of great use in analyzing the (post-)eruption flare- and CME-associated observational features. Such analysis is used to extend the standard 2D flare/CME models to 3D and to find potentially large implications of topology to understanding 3D reconnection and future applications to predictive space weather capabilities. Finally we, we demonstrate that when such NLFFF models are used as initial conditions to global MHD codes, they reproduce very well the observed CME morphology and propagation.

Facilitator
-Name:Shin Toriumi

Comment

Shin Toriumi, Ph.D.
Solar and Plasma Astrophysics Division
National Astronomical Observatory of Japan
2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan shin.toriumi@nao.ac.jp

9月26日(火)

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
9月26日(火曜日)13時30分~15時
場所
南棟2階会議室
講演者
藤原康徳

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

9月27日(水)

Campus
Mitaka
Seminar
SOKENDAI colloquium
Regularly Scheduled/Sporadic
Regular
Date and time
September 27 2017, 10:30 -12:00
Place
Lecture Room

Speaker1
Kei Ito
Affiliation
SOKENDAI M1 (Supervisor; Nobunari Kashikawa)
Title
z~5 HSC Protocluster survey

Speaker2
Takafumi Tsukui
Affiliation
SOKENDAI M1 (Supervisor; Satoru Iguchi, Hiroshi Nagai, Yuichi Matsuda)
Title
Radio Galaxy Formation

Facilitator
-Name:Misaki Ando

Comment
TV conference system is available connecting from Nobeyama, Hawaii, Mizusawa, and Okayama.

以上

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