論文

査読有り
2018年3月10日

Metallicity Distribution of Disk Stars and the Formation History of the Milky Way

Astrophysical Journal
  • Daisuke Toyouchi
  • ,
  • Masashi Chiba

855
2
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3847/1538-4357/aab044
出版者・発行元
Institute of Physics Publishing

We investigate the formation history of the stellar disk component in the Milky Way (MW) based on our new chemical evolution model. Our model considers several fundamental baryonic processes, including gas infall, reaccretion of outflowing gas, and radial migration of disk stars. Each of these baryonic processes in the disk evolution is characterized by model parameters that are determined by fitting to various observational data of the stellar disk in the MW, including the radial dependence of the metallicity distribution function (MDF) of the disk stars, which has recently been derived in the APOGEE survey. We succeeded to obtain the best set of model parameters that well reproduces the observed radial dependences of the mean, standard deviation, skewness, and kurtosis of the MDFs for the disk stars. We analyze the basic properties of our model results in detail to gain new insights into the important baryonic processes in the formation history of the MW. One of the remarkable findings is that outflowing gas, containing many heavy elements, preferentially reaccretes onto the outer disk parts, and this recycling process of metal-enriched gas is a key ingredient for reproducing the observed narrower MDFs at larger radii. Moreover, important implications for the radial dependence of gas infall and the influence of radial migration on the MDFs are also inferred from our model calculation. Thus, the MDF of disk stars is a useful clue for studying the formation history of the MW.

リンク情報
DOI
https://doi.org/10.3847/1538-4357/aab044
ID情報
  • DOI : 10.3847/1538-4357/aab044
  • ISSN : 1538-4357
  • ISSN : 0004-637X
  • SCOPUS ID : 85044078343

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