VALES - IV. Exploring the transition of star formation efficiencies between normal and starburst galaxies using APEX/SEPIA Band-5 and ALMA at low redshift
VALES - IV. Exploring the transition of star formation efficiencies between normal and starburst galaxies using APEX/SEPIA Band-5 and ALMA at low redshift
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VALES-IV。
DOI：
10.1093/mnras/stx3183
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发表时间：
2018
影响因子：
4.8
通讯作者：
Torstensson K
中科院分区：
文献类型：
--
作者：
Cheng C;Ibar E;Hughes T M;Villanueva V;Leiton R;Orellana G;Munoz Arancibia A;Lu N;Xu C K;Willmer C N A;Huang J;Cao T;Yang C;Xue Y Q;Torstensson K
In this work, we present new the Swedish-ESO PI receiver for the Atacama Pathfinder Experiment APEX/SEPIA Band-5 observations targeting the CO (J= 2–1) emission line of 24 Herschel-detected galaxies atz= 0.1–0.2. Combining this sample with our recent new Valparaíso ALMA Line Emission Survey (VALES), we investigate the star formation efficiencies [SFEs = star formation rate (SFR)/] of galaxies at low redshift. We find the SFE of our sample bridges the gap between normal star-forming galaxies and Ultra-Luminous Infrared Galaxies (ULIRGs), which are thought to be triggered by different star formation modes. Considering the SFE΄ as the SFR and theratio, our data show a continuous and smooth increment as a function of infrared luminosity (or star formation rate) with a scatter about 0.5 dex, instead of a steep jump with a bimodal behaviour. This result is due to the use of a sample with a much larger range of sSFR/sSFRmsusing LIRGs, with luminosities covering the range between normal and ULIRGs. We conclude that the main parameters controlling the scatter of the SFE in star-forming galaxies are the systematic uncertainty of the αCOconversion factor, the gas fraction, and physical size.
