Fast and inefficient star formation due to short-lived molecular clouds and rapid feedback
| العنوان: | Fast and inefficient star formation due to short-lived molecular clouds and rapid feedback |
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| المؤلفون: | Alexander P. S. Hygate, A. F. McLeod, Steven N. Longmore, Mélanie Chevance, Daniel T. Haydon, Linda J. Tacconi, Ewine F. van Dishoeck, J. M. Diederik Kruijssen, Andreas Schruba, Julianne J. Dalcanton |
| المصدر: | Nature |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | Physics, Multidisciplinary, 010308 nuclear & particles physics, Star formation, Molecular cloud, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Galaxy, Article, Interstellar medium, Stars, Supernova, 13. Climate action, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Flocculent spiral galaxy, Astrophysics::Galaxy Astrophysics, QB |
| الوصف: | The physics of star formation and the deposition of mass, momentum, and energy into the interstellar medium by massive stars (`feedback') are the main uncertainties in modern cosmological simulations of galaxy formation and evolution. These processes determine the properties of galaxies, but are poorly understood on the $\lesssim$100 pc scale of individual giant molecular clouds (GMCs) resolved in modern galaxy formation simulations. The key question is why the timescale for depleting molecular gas through star formation in galaxies ($t_{\rm dep}\approx 2$ Gyr) exceeds the dynamical timescale of GMCs by two orders of magnitude. Either most of a GMC's mass is converted into stars over many dynamical times, or only a small fraction turns into stars before the GMC is dispersed on a dynamical timescale. Here we report our observation that molecular gas and star formation are spatially de-correlated on GMC scales in the nearby flocculent spiral galaxy NGC300, contrary to their tight correlation on galactic scales. We demonstrate that this de-correlation implies rapid evolutionary cycling between GMCs, star formation, and feedback. We apply a novel statistical method to quantify the evolutionary timeline and find that star formation is regulated by efficient stellar feedback, driving GMC dispersal on short timescales (~1.5 Myr) due to radiation and stellar winds, prior to supernova explosions. This feedback limits GMC lifetimes to about one dynamical timescale (~10 Myr), with integrated star formation efficiencies of only 2-3%. Our findings reveal that galaxies consist of building blocks undergoing vigorous, feedback-driven lifecycles, that vary with the galactic environment and collectively define how galaxies form stars. Systematic applications of this multi-scale analysis to large galaxy samples will provide key input for a predictive, bottom-up theory of galaxy formation and evolution. Comment: Published in the May 23 issue of Nature; this is the authors' version before final edits; low-resolution versions of the Supplementary Videos are available as ancillary files in the arXiv source (see the link in the top right of this page), whereas the full-resolution versions are available with the Nature publication |
| وصف الملف: | application/pdf |
| اللغة: | English |
| تدمد: | 1476-4687 0028-0836 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::be9a4e942baea348e2ef21aa95ec2989 http://europepmc.org/articles/PMC6544524 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....be9a4e942baea348e2ef21aa95ec2989 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Springer Verlag. | تدمد: | 14764687 00280836 |
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