月別アーカイブ: 2014年5月

国立天文台特別公開講座/総研大入試ガイダンス(関東会場)

 2014年5月24日(土)、国立天文台三鷹キャンパスに於いて、国立天文台特別公開講演および総研大天文科学専攻入試ガイダンスが行われました。本年は天候にも恵まれ、総勢約50名の方々にご来場いただきました。
 本年度はテーマを“国立天文台で究める最新の宇宙像”として,成田憲保特任助教(太陽系外惑星探査プロジェクト)、富阪幸治教授(理論研究部)、麻生洋一准教授(重力波プロジェクト推進室)、兒玉忠恭准教授(ハワイ観測所)によって、理論・観測における最新の成果と今後の天文学界の展望等についての講演が行われました。特に、成田憲保特任助教による“すばる、岡山、そしてTMTで挑む第2の地球探し”では、地球外生命体の存在についてなど、参加者からの熱心な質問により、白熱した議論が繰り広げられました。

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国立天文台特別公開講座/総研大入試ガイダンス(関西会場)

 2014年5月17日(土)、メルパルク京都で行われた国立天文台特別公開講座/総研大天文科学専攻入試ガイダンスには、25名の方々にご来場いただきました。“国立天文台で究める最新の宇宙像”というテーマのもと、林左絵子准教授(ハワイ観測所)、本間希樹准教授(水沢VLBI観測所)、小嶋崇文 助教(先端技術センター)、末松芳法准教授(ひので科学プロジェクト)の4名の講師による講演が行われました。
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clustering properties of z~2 galaxies by extremely wide field galaxy survey etc.

[Speaker1]
Shogo Ishikawa , D1, SOKENDAI, Mitaka(supervisor: Nobunari Kashikawa)
[Title]
clustering properties of z~2 galaxies by extremely wide field galaxy survey

[Speaker2]
Masafusa Onoue , M2, SOKENDAI, Mitaka(supervisor: Nobunari Kashikawa)
[Title]
The Selection Method for Finding High-z Quasar
[Abstract]
In this colloquium, I’d like to start with explaining how to estimate redshift of unknown objects, and why it is important. Then, I will show you the progress of the development of effective quasar selection method that I have been working on.

Investigating the coevolution between SMBHs and galaxies at z~3 -error estimate- etc.

[Speaker1]
Yuriko Saito, D2, SOKENDAI, Mitaka(supervisor: Masatoshi Imanishi)
[Title]
Investigating the coevolution between SMBHs and galaxies at z~3 -error estimate-
[Abstract]
In the local universe, there is a tight correlation between the masses of super massive black holes (SMBHs) and stars in the spheroidal components (bulge and elliptical galaxies), suggesting that their formation is physically closely related. Various models assuming different physical mechanisms are proposed to explain the observational result at z=0. Since these models predict different redshift evolution of the SMBH-spheroid mass ratio, it is important to observationally constrain the mass ratio at high redshift.

To achieve our goal, we have been carried out both spectroscopic and imaging observations, and obtained 37 spectroscopic data and 9 imaging data of z~3 quasars. We completed to analyze spectroscopic data and obtained BH masses for 28 out of 37 objects.
Now we have started imaging data analysis and obtained preliminary result of SMBH-spheroid mass ratio at z~3 (previous talk).
However, there is too large uncertainty to constrain the mass ratio and it is important to reduce the error.

There are three noise sources that contribute to the total error of SMBH-spheroid mass ratio.
1) BH mass error : BH mass is estimated from the Balmer beta emission line width and AGN luminosity at 5100A. So this error is dominated by line width error (i.e. spectral fitting error) and luminosity error (i.e. S/N ratio at ~5100A), and has been already estimated for 28 objects.
2) Spheroidal luminosity error : spheroidal luminosity is estimated by decomposing AGN and host galaxy radiation by fitting both components.Thus, we should consider the fitting error carefully and try to reduce it.
3) Mass to luminosity ratio (M/L) error : to estimate spheroidal mass,we convert spheroidal luminosity to mass using M/L ratio which is derived from host galaxy color in this study. Therefore, accurate M/L determination and reducing its error is crucial.

In my past talks, I have been presented BH mass estimates, our preliminary results of spheroidal mass estimates and the redshift evolution of SMBH-spheroid mass ratio.
In this talk, I will explain errors that we should care for the accurate mass ratio determination with introducing related papers,and present current progress of error estimate.

[Speaker2]
Anjali John, D3, SOKENDAI, Mitaka(supervisor: Y.Suematsu)
[Title]
Unipolar Appearance and Disappearance of the Sun’s Polar Magnetic Patches