We revisit the proposed extended Schmidt law, which posits that the star formation efficiency in galaxies depends on the stellar mass surface density, by investigating spatially resolved star formation rates (SFRs), gas masses, and stellar masses of star formation regions in a vast range of galactic environments, from the outer disks of dwarf galaxies, to spiral disks and to merging galaxies, as well as individual molecular clouds in M33. We find that these regions are distributed in a tight power law as Sigma(SFR) proportional to (Sigma(0.5)(star)Sigma(gas))(1.09), which is also valid for the integrated measurements of disk and merging galaxies at high-z. Interestingly, we show that star formation regions in the outer disks of dwarf galaxies with Sigma(SFR) down to 10(-5) M(circle dot)yr(-1) kpc(-2), which are outliers of both the Kennicutt-Schmidt and Silk-Elmegreen laws, also follow the extended Schmidt law. Other outliers in the Kennicutt-Schmidt law, such as extremely metal-poor star formation regions, also show significantly reduced deviation from the extended Schmidt law. These results suggest an important role for existing stars in helping to regulate star formation through the effect of their gravity on the midplane pressure in a wide range of galactic environments.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/627041 |
| Date | 01 February 2018 |
| Creators | Shi, Yong, Yan, Lin, Armus, Lee, Gu, Qiusheng, Helou, George, Qiu, Keping, Gwyn, Stephen, Stierwalt, Sabrina, Fang, Min, Chen, Yanmei, Zhou, Luwenjia, Wu, Jingwen, Zheng, Xianzhong, Zhang, Zhi-Yu, Gao, Yu, Wang, Junzhi |
| Contributors | Univ Arizona, Steward Observ, Univ Arizona, Dept Astron |
| Publisher | IOP PUBLISHING LTD |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | © 2018. The American Astronomical Society. All rights reserved. |
| Relation | http://stacks.iop.org/0004-637X/853/i=2/a=149?key=crossref.8d59b9b2064521e8038c2ffd5e7c9a7a |
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