发稿时间:2018-10-11浏览次数:80

USTC Astronomy Seminar Series: 2018 Fall
Star Formation Efficiency of the Galaxies at z ~ 0.15
程诚助理研究员
国家天文台
2018/10/11, 4:00pm , the 19th-floor Observatory Hall
In this talk, I will briefly introduce our recent Valparaíso ALMA Line Emission Survey (VALES) project as well as the new APEX/SEPIA Band-5 observations targeting the low-J CO emission line of 63 Herschel-detected galaxies at z~0.15. We investigate the star formation efficiencies (SFEs = SFR/M(H2)) of galaxies at low redshift. We find the SFE of our sample bridges the gap between normal star-forming galaxies and UltraLuminous Infrared Galaxies (ULIRGs), which are thought to be triggered by different star formation modes. Considering the SFE as the SFR to L(CO) ratio, our data show a continuous and smooth increasement as a function of infrared luminosity (or SFR) 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/sSFRms using LIRGs, with luminosities covering the range between normal and ULIRGs. We conclude that the main parameters controlling the catter of the SFE in star-forming galaxies are the systematic uncertainty of the α(CO) conversion factor, the gas fraction and physical size.
 程诚, 2008年于中国科学技术大学近代物理系本科毕业, 2013年于中国科学院高能物理研究所博士毕业, 2013-2017年在中国科学院国家天文台中智中心做博士后, 2016年-2018年访问智利瓦尔帕莱索大学, 现任国家天文台中智中心助理研究员。 参与了CANDELS, CLAUDS等国际巡天项目, 曾申请到过MMT, Palomar, ALMA, Magellan,Gemini等望远镜观测时间, 主要研究方向是低质量星系的观测性质, 星系的红外及(亚)毫米波段性质。