7月26日（水）13：30～14：30 理論コロキウム コスモス会館会議室
Jul 26 Wed DTA colloquium Conference Room, Cosmos Lodge
7月26日（水）15：00～ 太陽系科学セミナー 輪講室
Jul 26 Wed Solar System Science Seminar Rinko-shitsu,Main Bldg.(East)
7月28日（金）13：30～15：00 太陽天体プラズマセミナー 院生セミナー室
Jul 28 Fri Solar and Space Plasma Seminar Student Seminar Room, Subaru Bldg.
詳細は以下をご覧下さい。
7月26日（水）
- Campus
- Mitaka
- Seminar
- DTA colloquium
Regularly Scheduled - Date and time
- 26th July 2017, 13:30-14:30
- Place
- Conference Room, Cosmos Lodge
- Speaker
- Jean Coupon
- Affiliation
- University of Geneva
- Title
- Probing the galaxy-mass connection in TeraByte-scale imaging surveys
- Abstract
- (optional) The past decade has seen the emergence of new techniques and exciting discoveries powered by wide-field imaging surveys from the UV to the near-IR domain. Owing to gravitational lensing, galaxy clustering and abundance matching (to name but a few), coupled with advanced statistical interpretation, the informative power of astronomical imaging surveys has significantly increased. In particular, the connection between galaxies and dark matter, a keystone in cosmology and the study of galaxy evolution, has widely gained from this “scale revolution” and the future is bright, as the next experiments such as HSC, LSST, Euclid or WFIRST are dedicated “survey” machines that will further increase imaging data by orders of magnitude (without mentioning the tremendous gain in image resolution, time domain and deep near-IR imaging). I will focus my talk on reviewing the main techniques to connect galaxies and dark matter in the context of wide-field surveys and I will show some concrete examples of applied data analysis in the CFHTLenS and COSMOS projects, showing that these techniques are now well proven, although the challenges in reducing some critical systematic uncertainties are ahead of us.
- Facilitator
- -Name：Tomoya Takiwaki
- Comment
- in English
7月26日（水）
- キャンパス
- 三鷹
- セミナー名
- 太陽系科学セミナー
- 定例・臨時の別
- 定例
- 日時
- 7月26日（水曜日）15時00分～
- 場所
- 輪講室
- 講演者
- 石黒正晃
- タイトル
- 【活動的小惑星勉強会 3】 小惑星衝突現象の観測研究
- Abstract
- 2017年7月現在、約20個の活動的小惑星が確認されている。これらの
天体は、様々なメカニズム（氷の昇華や衝突、自転崩壊など）によって小惑星表
面の固体微粒子が惑星間空間に放出された結果、彗星状に観測された小惑星であ
ると考えられている。中でも (596) Scheilaは衝突によってダスト放出が確認さ
れた唯一の天体である。
最近の私たちのグループによる研究から、2010年に発見されたリニア彗星
（P/2010 A2）は、catastrophic collisionによってダスト雲が形成された可能
性が高いことがわかってきた([1][2])。本講演では、活動的小惑星の中でも衝突
に起因する天体にテーマを限定して研究成果を紹介する。
参考文献
[1] Kim, Y., Ishiguro, M., Lee, M, ApJ Letter 842, 2, L23, 2017 [2] Kim, Y., Ishiguro, M., Michikami, T., Nakamura, A.M., AJ 153, 5, 228, 2017 - 連絡先
-
-名前：脇田茂
-名前：松本晃治
-名前：土屋智恵 - 備考
- テレビ会議による参加も可
7月28日（金）
- Campus
- Mitaka
- Seminar
- Solar and Space Plasma Seminar
- Regularly Scheduled/Sporadic
- Regular
- Date and time
- 28 July (Fri), 13:30-15:00
- Place
- Student Seminar Room, Subaru Bldg.
- Speaker
- Mugnus Woods
- Affiliation
- UCL-Mullard Space Science Laboratory
- Title
- Investigations of pre-flare activity with Hinode/EIS and IRIS
- Abstract
- On the 29 March 2014 NOAA active region (AR) 12017 produced an X1 flare which was simultaneously observed by an unprecedented number of observatories. In this talk, we present the results of an investigation into the pre-flare period of this flare from 14:00 UT until 19:00 UT using joint observations made by the Interface Region Imaging Spectrometer (IRIS) and the Hinode Extreme Ultraviolet Imaging Spectrometer (EIS). Spectral lines providing coverage of the solar atmosphere from chromosphere to the corona were analysed to investigate pre-flare activity within the AR. We have revealed evidence of strongly blue-shifted plasma flows, with velocities up to 200 km/s, being observed 40 minutes prior to flaring. These flows are located along the filament present in the active region and are both spatially discrete and transient. In order to constrain the possible explanations for this activity, we undertook non-potential magnetic field modelling of the active region. This modelling indicates the existence of a weakly twisted flux rope along the polarity inversion line in the region where a filament and the strong pre-flare flows are observed. We then discuss how these observations relate to the current models of flare triggering and conclude that the most likely drivers of the observed activity are internal reconnection in the flux rope, early onset of the flare reconnection, or tether cutting reconnection along the filament.
- Facilitator
- -Name：Shin Toriumi
- Comment
以上