論文

査読有り 筆頭著者 責任著者
2019年12月1日

CO Multi-line Imaging of Nearby Galaxies (COMING). VI. Radial variations in star formation efficiency

Publications of the Astronomical Society of Japan
  • Kazuyuki Muraoka
  • Kazuo Sorai
  • Yusuke Miyamoto
  • Moe Yoda
  • Kana Morokuma-Matsui
  • Masato I N Kobayashi
  • Mayu Kuroda
  • Hiroyuki Kaneko
  • Nario Kuno
  • Tsutomu T Takeuchi
  • Hiroyuki Nakanishi
  • Yoshimasa Watanabe
  • Takahiro Tanaka
  • Atsushi Yasuda
  • Yoshiyuki Yajima
  • Shugo Shibata
  • Dragan Salak
  • Daniel Espada
  • Naoko Matsumoto
  • Yuto Noma
  • Shoichiro Kita
  • Ryusei Komatsuzaki
  • Ayumi Kajikawa
  • Yu Yashima
  • Hsi-An Pan
  • Nagisa Oi
  • Masumichi Seta
  • Naomasa Nakai
  • 全て表示

71
6
開始ページ
S15
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1093/pasj/psz015
出版者・発行元
Oxford University Press (OUP)

<title>Abstract</title>
We examined radial variations in molecular-gas based star formation efficiency (SFE), which is defined as star formation rate per unit molecular gas mass, for 80 galaxies selected from the CO Multi-line Imaging of Nearby Galaxies project (Sorai et al. 2019, PASJ, 71, S14). The radial variations in SFE for individual galaxies are typically a factor of 2–3, which suggests that SFE is nearly constant along the galactocentric radius. We found an averaged SFE in 80 galaxies of (1.69 ± 1.1) × 10−9 yr−1, which is consistent with Leroy et al. (2008, AJ, 136, 2782) if we consider the contribution of helium to the molecular gas mass evaluation and the difference in the assumed initial mass function between the two studies. We compared SFE among different morphological (i.e., SA, SAB, and SB) types, and found that SFE within the inner radii (r/r25 &amp;lt; 0.3, where r25 is the B-band isophotal radius at 25 mag arcsec−2) of SB galaxies is slightly higher than that of SA and SAB galaxies. This trend can be partly explained by the dependence of SFE on global stellar mass, which probably relates to the CO-to-H2 conversion factor through the metallicity. For two representative SB galaxies in our sample, NGC 3367 and NGC 7479, the ellipse of r/r25 = 0.3 seems to cover not only the central region but also the inner part of the disk, mainly the bar. These two galaxies show higher SFE in the bar than in the spiral arms. However, we found an opposite trend in NGC 4303; SFE is lower in the bar than in the spiral arms, which is consistent with earlier studies (e.g., Momose et al. 2010, ApJ, 721, 383). These results suggest a diversity of star formation activities in the bar.

リンク情報
DOI
https://doi.org/10.1093/pasj/psz015
共同研究・競争的資金等の研究課題
近傍銀河の大規模分子ガス撮像サーベイから探る、棒渦巻銀河における星形成の多様性
URL
http://academic.oup.com/pasj/article-pdf/71/Supplement_1/S15/31573429/psz015.pdf
ID情報
  • DOI : 10.1093/pasj/psz015
  • ISSN : 0004-6264
  • eISSN : 2053-051X

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