| Project/Area Number |
19K21056
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| Project/Area Number (Other) |
18H05875 (2018)
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| Research Category |
Grant-in-Aid for Research Activity Start-up
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| Allocation Type | Multi-year Fund (2019)
Single-year Grants (2018) |
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| Review Section |
0204:Astronomy, earth and planetary science, and related fields
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| Research Institution | National Astronomical Observatory of Japan |
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Principal Investigator |
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| Project Period (FY) |
2018-08-24 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | 銀河考古学 / 光赤外線天文学 / 近傍銀河 / 銀河形成 / 恒星種族 / 光赤外天文学 |
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| Outline of Research at the Start |
すばる望遠鏡の超広視野カメラを用いて、複数の近傍円盤銀河の外縁部を探査する「すばる近傍宇宙論サーベイ」を行い、円盤銀河が一般的に外縁部構造を持つか否か、またその恒星種族 (年齢/金属量)が共通なのか統計的に明らかにする。対象銀河のうち、補助事業期間中に観測が実施された領域について、恒星分離に基づいた測光解析を行い、 [1] 外縁部構造の有無とその恒星種族、[2] 衛星銀河の空間分布と総数、恒星ストリーム等サブ構造を調べる。
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| Outline of Final Research Achievements |
We have conducted the wide-field photometric survey of nearby massive galaxies using Hyper Suprime-cam on Subaru Telescope.
For the M81 galaxy, the structural parameters, total luminosities, metallicity distributions, and metallicity dispersions of eight satellite galaxies were derived. Also, we discovered two new satellite candidates around M81, one of which is the faintest and the most metal-poor galaxies in the M81 group. The luminosity functions of young stellar systems around M81 imply continuous star formation in the recent past, supporting the idea that they are genuinely new stellar systems resulting from triggered star formation in gaseous tidal debris of M81-M82-NGC3077 interactions.
Following to the M81 survey, we were awarded ten nights as the intensive program of Subaru Telescope open-use to cover nearby galaxies using HSC. Among the six target galaxies, the observations of four galaxies were executed in 2019.
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| Academic Significance and Societal Importance of the Research Achievements |
円盤銀河が一般的に、銀河系のように複雑で豊富な外縁部構造を持つか否か、またそれに含まれる恒星の年齢や金属量が共通なのかどうかは、銀河の進化過程における矮小銀河降着の影響を測る上で非常に重要な問題である。本研究では、銀河系やアンドロメダ銀河が含まれる局所銀河群を超えてさらに遠くの大型円盤銀河をターゲットに、すばる望遠鏡の超広視野カメラを用いることで、その銀河を構成する個々の星を捉え、非常に暗い外縁部構造と周辺の衛星銀河の性質を詳細に明らかにした。
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