Home > VLBIコロキウム | その他 | 国立天文台談話会 > 2016.3.21-3.27

2016.3.21-3.27

3月22日(火)10:00~17:30  星震学と銀河考古学ワークショップ   コスモス会館会議室
Mar 22 Tue   Workshop on Galactic archaeology – Asteroseismology   Conference Room, Cosmos Lodge

3月24日(木)15:00~16:00   VLBIコロキウム  中央棟(南)2F VLBIセミナー室
Mar 24 Thu   VLBI Colloquium    VLBI Seminar Room, Main Bldg. (South) 2F

3月24日(木)15:00~16:00  先端技術セミナー    中央棟(東)輪講室
Mar 24 Thu   ATC Seminar        Rinko-shitsu,Main Bldg.(East)

3月24日(木)16:00~17:00  国立天文台談話会   大セミナー室
Mar 24 Thu   NAOJ Seminar          Large Seminar Room

3月25日(金)16:00~17:00  国立天文台談話会   大セミナー室
Mar 25 Fri   NAOJ Seminar          Large Seminar Room

詳細は以下をご覧下さい。

3月22日(火)

Campus
Mitaka
Seminar
Workshop on Galactic archaeology – Asteroseismology
Regularly Scheduled/Sporadic
Sporadic
Date and time
10:00 – 17:30, Mar 22, 2016
Place
Conference Room, Cosmos Lodge
Facilitator
-Name:Tadafumi Matsuno, Wako Aoki, Nobuo Arimoto, Takuji Tsujimoto
Comment
See the link below for further details.
http://optik2.mtk.nao.ac.jp/ws/ws20160322.html

3月24日(木)

キャンパス
三鷹
セミナー名
VLBIコロキウム
定例・臨時の別
定例
日時
 3月24日(木曜日)15:00 ~ 16:00
場所
 中央棟(南)2階VLBIセミナー室
講演者
 David D. Mulcahy
所属
 Jodrell Bank Centre for Astrophysics, University of Manchester
タイトル
Observing nearby spiral galaxies with a new generation of radio telescopes
Abstract
Magnetic fields are an essential part of the interstellar medium, both within our own Galaxy and in other external star-forming galaxies. In spiral galaxies these fields are thought to arise due to differential and helical turbulence: the so-called ”dynamo model”. They govern the propagation of relativistic cosmic rays, controlling their density and distribution, and dominate the energy budget in the extended galactic disk.

There is increasing evidence that magnetic fields can extend deep into the intergalactic space; however as it is far from regions of acceleration, the synchrotron emission is weak due to lack of cosmic rays electrons which suffer from various loss processes.
Fortunately, low energy electrons which emit emission at low frequencies suffer less from energy loss processes and are expected to travel further, especially in the presence of ordered magnetic fields.

The first part of this talk will present low frequency radio observations of the face-on galaxy, M51, from the LOFAR telescope. In combination with novel theoretical models of cosmic ray propagation, I will address multiple outstanding questions in galactic astrophysics: how far do galactic magnetic disks extend and what is their structure; what is the dominant mechanism of cosmic ray propagation in these regions? Using these theoretical models, the cosmic ray confinement time within the galaxy can be accurately calculated.

In the second part of this talk, I shall present new JVLA observations of the face-on spiral galaxy, NGC 628, at 2-4 GHz. The observations aim to increase our understanding of the disk-halo interaction which is vital to explain the evolution of spiral galaxies. Studying a face-on spiral galaxy like NGC 628 helps the separation of magnetic field components in 3D. Thus through the technique of Rotation Measure Synthesis, any Faraday rotation observed is due solely to the vertical magnetic field. This would help find turbulent magnetic fields being carried out from the disk and would provide an important mechanism for the dynamo to amplify the ordered magnetic field without quenching.

Language
English
連絡先
 名前:酒井 大裕
備考
テレビ参加可

3月24日(木)

セミナー名
先端技術セミナー(ATC seminar)
キャンパス
三鷹
定例・臨時の別
臨時
日時
3月24日(木曜日)15時~16時
場所
輪講室
講演者
秋山永治
所属
チリ観測所(三鷹)
タイトル
ALMA望遠鏡の科学的成果:ALMA望遠鏡が映し出した星と惑星系の誕生の姿
Abstract
ALMA望遠鏡はかつてない高感度に加えて、高空間分解能を備えている。
2014年に最大15kmにも及ぶ基線長で科学評価観測(Science Verification)が遂行され、衝撃的な観測結果が発表されている。
特に、0.03秒角以下の空間分解能で見たおうし座HL星(HL Tau)に付随する原始惑星系円盤は、惑星系が形成されていく様子を彷彿とさせる複数の円環状の隙間構造を映し出しており、惑星形成研究に大きなインパクトを与えた。そして、惑星形成の研究に新たな革命をもたらす画像となっている。
本講演では、星・惑星系形成の観測を中心にこれまでALMAで明らかになった極めて大きな科学成果について紹介する。
Title
ALMA’s scientific output: A picture of star and planetary system formation by the ALMA
Abstract
ALMA achieves unprecedented sensitivity and spatial resolution.
Since the science verification observations with baselines of 15 km was conducted in 2014, impressive results have been reported.
In particular, the images of a protoplanetary disk associated with the HL Tauri obtained by less than 0.03 asec resolution shows multiple ring gap structure that is reminiscent of planetary system formation and have an impact on planetary science.
In this talk, I focus on observations of star and planetary system formation and shows outstanding scientific outputs that the ALMA has disclosed today.

連絡先
-名前: 松尾 宏
備考
日本語での講演(presentation in Japanese)

3月24日(木)

キャンパス
三鷹
セミナー名
国立天文台談話会
定例・臨時の別
臨時
日時
3月24日(木) 16:00-17:00
場所
大セミナー室
講演者
Donald Wayne Kurtz
所属
Jeremiah Horrocks Institute, University of Central Lancashire
タイトル
“Asteroseismology: A New Keplerian Revolution”
Abstract
In 1926 in the opening paragraph of his now-classic book, The Internal Constitution of the Stars,Sir Arthur Eddington lamented, “What appliance can pierce through the outer layers of a star and test the conditions within?” While he considered theory to be the proper answer to that question, there is now an observational answer: asteroseismology. We are in a time of a significant advance in our understanding of stellar astrophysics with data from the Kepler Mission.
From its rich 4-year data set nearly 5000 exoplanet candidates have been discovered – the majority of all known. Kepler has also improved our ability to see pulsations and variability in stars by 100 to 1000 times compared with ground-based telescopes, allowing us to probe stars using asteroseismology.
We are seeing as never before: heartbeat stars, novel eclipsing stars, spots, flares and magnetic cycles as in our own Sun.
Astrophysics that used to be theoretical is now also observational: internal stellar rotation from core to surface; gravitational lensing in eclipsing binary stars;Doppler boosting; multiple pulsation axes; period doubling; tidal excitation in highly eccentric binary stars. Kepler data for solar-like stars are now comparable to data for the Sun seen as a star, giving us masses, radii and ages for hundreds of single stars, allowing determination of their orbiting planets’ sizes, and giving new constraints on stellar evolution theory.
It is now even possible to see into the cores of red giants and observe which stars are hydrogen shell-burning and which also are helium-core burning.
This talk will introduce the concepts of asteroseismology and show a selection of exciting observational results from the Kepler mission.
連絡先
-名前: 阿久津 智忠

3月25日(金)

キャンパス
三鷹
セミナー名
国立天文台談話会
定例・臨時の別
定例
日時
3月25日(金) 16:00-17:00
場所
大セミナー室
講演者
櫻井 隆
所属
国立天文台太陽天体プラズマ研究部
タイトル
太陽磁場の研究:歴史と今後
Abstract
太陽黒点の磁場がゼーマン効果の観測により発見されたのは1908年のことである。これは眼視観測であったが、その後、磁場観測装置(マグネトグラフ)は様々な改良が加えられ、黒点数の11年周期変動に代表される太陽の磁気活動の多様な特徴を明らかにしてきた。日本での磁場観測は海野(1956)の基礎理論に始まり、2006年に打ち上げられたひので衛星に高性能の磁場観測装置が搭載されめざましい成果を上げているほか、地上観測では第4世代の観測装置が三鷹で運用中である。現在における太陽物理学の未解決問題と、それらがハワイに建設中の口径4mの太陽望遠鏡DKISTや計画提案中のSOLAR-C衛星によってどう明らかになって行くか、将来の展望を述べる。
連絡先
-名前: 阿久津 智忠

以上

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