Ia型超新星的诞生率以及光度与寄主星系的统计关系  

Dependence of SNe Ia Rates and Luminosities on Host Galaxies

作　　者：梁文科[1,2,3] 王建成[1,2] 

机构地区：[1]中国科学院国家天文台/云南天文台,昆明650011 [2]中国科学院天体结构与演化重点实验室,昆明650011 [3]中国科学院大学,北京100049

出　　处：《天文学进展》2013年第4期411-424,共14页Progress In Astronomy

基　　金：973项目(2009CB824800);国家自然科学基金(11133006;11163006;11173054);中科院政策研究项目(KJCX2-YW-T24)

摘　　要：当前的研究表明,在小质量星系或者恒星形成率高的星系中,Ia型超新星有高的诞生率。没有经过光度经验校正,在大质量、高金属丰度、年老的、早型演化的星系中的Ia型超新星更暗;但是经过光度校正以后,亮的超新星更倾向于出现在大质量、高金属丰度、年老的、早型演化的星系中。因为高金属丰度的前身星系统是富中子的,使得在超新星爆发过程中物质更稳定地燃烧,这样产生的56Ni就很少,而56Ni提供的衰变能是Ia型超新星光度的重要来源,会导致高金属丰度环境下的Ia型超新星光变曲线下降更快而且也更暗;但是经过光度校正以后,高金属丰度环境下的Ia型超新星更亮。不同星系环境下的金属丰度不同,因而Ia型超新星56Ni产生率不同,这可能是对超新星光度与星系统计关系的最合理解释。综述了Ia型超新星的诞生率以及光度与寄主星系的统计关系。We mainly present the dependence of SNe Ia rate and luminosity on their host galaxies. Firstly, we show that the host galaxy mass is lower or host star-formation rate is higher, SNe Ia rate will be larger. Secondly, we show that before light-curve correction, dimmer SNe Ia fluently occur in higher mass, higher star-formation rate, higher metal abundance, or older stellar galaxy system. However, after light-curve correction, brighter SNe Ia fluently occur in higher mass, higher star-formation rate, higher metal abundance, or older stellar galaxy system. Higher-metallicity pro- genitors are more neutron rich, producing more stable burning products relative to radioactive 56Ni. Since SNe Ia explosions are powered by the radioactive decay 56Ni, it is widely accepted that the intrinsic variation in SNe Ia brightness and decline rate is primarily driven by the amount of 56Ni present in SNe explosion, where more luminous and much slowly declining explosions are powered by more 56Ni, hence, under higher-metallicity circumstances, SNe Ia are dimmer. Whereas, after light-curve correction, SNe Ia in higher-metallicity progenitors are brighter. Therefore, the metallic- ity diversity is responsible for the dependence of SNe Ia luminosties on host galaxies.

关 键 词：超新星 诞生率 光度 寄主星系 

分 类 号：P145.3[天文地球—天体物理]