Stellar mass estimation based on IRAC photometry for Spitzer SWIRE-field galaxies  

作　　者：Yi-Nan Zhu Hong Wu Hai-Ning Li Chen Cao 

机构地区：[1]National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China [2]Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China [3]Graduate University of Chinese Academy of Sciences, Beijing 100049, China [4]Institute of Space Science and Physics, Shandong University at Weihai, Shandong 264209

出　　处：《Research in Astronomy and Astrophysics》2010年第4期329-347,共19页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10833006 and 10773014);the 973 Program grant 2007CB815406

摘　　要：We analyze the feasibility of estimating the stellar mass of galaxies by mid-infrared luminosities based on a large sample of galaxies cross-identified from Spitzer SWIRE fields and the SDSS spectrographic survey.We derived the formulae to calculate the stellar mass by using IRAC 3.6μm and 4.5μm luminosities.The massto-luminosity ratios of IRAC 3.6μm and 4.5μm luminosities are more sensitive to the star formation history of galaxies than to other factors,such as the intrinsic extinction,metallicity and star formation rate.To remove the effect of star formation history,we used g-r color to recalibrate the formulae and obtain a better result.Researchers must be more careful when estimating the stellar mass of low metallicity galaxies using our formulae.Due to the emission from dust heated by the hottest young stars,luminous infrared galaxies present higher IRAC 4.5μm luminosities compared to IRAC 3.6μm luminosities.For most of type-Ⅱ AGNs,the nuclear activity cannot enhance 3.6μm and 4.5μm luminosities compared with normal galaxies.Star formation in our AGNhosting galaxies is also very weak,almost all of which are early-type galaxies.We analyze the feasibility of estimating the stellar mass of galaxies by mid-infrared luminosities based on a large sample of galaxies cross-identified from Spitzer SWIRE fields and the SDSS spectrographic survey.We derived the formulae to calculate the stellar mass by using IRAC 3.6μm and 4.5μm luminosities.The massto-luminosity ratios of IRAC 3.6μm and 4.5μm luminosities are more sensitive to the star formation history of galaxies than to other factors,such as the intrinsic extinction,metallicity and star formation rate.To remove the effect of star formation history,we used g-r color to recalibrate the formulae and obtain a better result.Researchers must be more careful when estimating the stellar mass of low metallicity galaxies using our formulae.Due to the emission from dust heated by the hottest young stars,luminous infrared galaxies present higher IRAC 4.5μm luminosities compared to IRAC 3.6μm luminosities.For most of type-Ⅱ AGNs,the nuclear activity cannot enhance 3.6μm and 4.5μm luminosities compared with normal galaxies.Star formation in our AGNhosting galaxies is also very weak,almost all of which are early-type galaxies.

关 键 词：galaxies：stellar content - galaxies：active - infrared：galaxies 

分 类 号：P148[天文地球—天体物理] TM623.7[天文地球—天文学]