2011年度・東京大学・天文学教育研究センター・談話会†
次回の談話会†
第182回 2011/07/28(木) 15:30~16:30
上塚 貴史 氏 (東大・天文センター)
"Mid-infrared spectral monitoring toward AGB stars - Probing the formation of circumstellar dust - "
Asymptotic giant branch (AGB) stars are the stars in the final evolutionary stage of low-
and intermediate-mass stars. They are known to show mass-loss events caused by their stellar wind,
and the events play an important role for chemical evolution of the universe.
The stellar wind is thought to be driven by radiative pressure on dust formed around the central star.
After the grains are formed, they are accelerated by the radiation from inner region,
and the gaseous material is accelerated by the gas-dust collisions.
This scenario has not been fully investigated by observations. It is important to probe
when, where and what kind of grains are formed around the region where the stellar wind is driven,
and mid-infrared spectral monitoring is one of useful methods.
As an example, I will present our monitoring observation toward HV2446 and IRAS04544-6849,
which are Mira type variables in the Large Magellanic Cloud, taken with Spitzer Space Telescope.
Both objects showed time variation of silicate features. These variations can be explained
mainly by the temperature variation caused by the luminosity variation of the central star.
However, the strength and the shape of the feature around the visual maximum phase cannot be
explained by this effect. This suggests possibility of the dust formation around this phase.
From this result, the monitoring observations are thought to have big potential to probe the grain formation events.
In this talk, I will discuss about this result and the usefulness of long-term monitoring observations with mini-TAO and TAO.
東京大学・天文学教育研究センターでは2003年4月から, 院生コロキウムに引き続き, 談話会を開いています.
第一線で活躍されている研究者の方々を講師にお招きし, 最先端の研究成果をお話しいただきます.
講師の方には, 大学院生の参加者のことも考慮し, レビュー的な側面も含めた上で, ご自身の研究紹介をお願いしています.
タイムテーブル†
| 13:30-14:30 | 院生コロキウム | 講義室 |
| 15:30-16:30 | 談話会 | 講義室 |
| 16:30- | お茶の時間 | 講義室横のお茶部屋~講師の方を交えて~ |
世話人†
- 田中 培生
- 諸隈 智貴: tmorokuma_at_ioa.s.u-tokyo.ac.jp (_at_を@に置き換えてください)
| # | 日付 | 講演者 (所属) | タイトル |
| 182 | 2011/07/28(木) | 上塚 貴史 氏 (東京大学・天文センター) | Mid-infrared spectral monitoring toward AGB stars - Probing the formation of circumstellar dust - |
| - | 2011/09/01(木) | 眞山 聡 氏 (総研大) | 未定 |
| - | 2011/09/29(木) | 西澤 淳 氏 (東京大学・IPMU) | 未定 |
終了した談話会†
| # | 日付 | 講演者 (所属) | タイトル |
| 177 | 2011/05/19(木) | 田村 陽一 氏 (東京大学・天文センター) | 「ASTE搭載用超伝導転移端センサ型ボロメータカメラとALMA初期科学運用」 |
| 178 | 2011/06/16(木) | Michael Richmond 氏 (Rochester Institute of Technology) | "Looking for eclipsing RR Lyr stars in the MACHO database" |
| 179 | 2011/06/30(木) | 田中 賢幸 氏 (東京大学・IPMU) | "A new method to identify AGNs and the nature of low-luminosity AGNs" |
| 180 | 2011/07/07(木) | 橋本 哲也 氏 (国立天文台) | "A hint of AGN feedback: Shock heating of ISM induced by a jet in NGC 1068" |
| 181 | 2011/07/21(木) | 柏川 伸成 氏 (国立天文台) | 「AKB48 vs. NMB48 vs. SKE48, そして LAE45vs.LAE54」」, "Completing the Census of Lyα Emitters at the Reionization Epoch" |
過去の談話会†
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