Ia超新星的几个问题

首先利用Ａｓｉａｇｏ 超新星星表对Ｉａ 超新星作了统计分析。其次用具有精确测光的Ｉａ 超新星对其均匀性及多样性进行了研究。旋涡星系中Ｉａ 超新星的产生率比椭圆星系的要高。最亮的Ｉａ 超新星只出现于晚型旋涡星系中；而旋涡星系及早型的椭圆星系都是暗Ｉａ 超新星的寄主星系。离星系中心越近Ｉａ 超新星的光度弥散有增加的趋势，但这一趋势对蓝Ｉａ 超新星不明显。利用色指数可将Ｉａ 超新星划分为蓝超新星及红超新星。蓝Ｉａ 超新星构成了相对均匀的Ｉａ 超新星样本，是较好的距离指示器；而红Ｉａ 超新星的存在则表明了Ｉａ 超新星整体多样性的特点。最后，我们还探讨了Ｉａ 超新星中碳点火的非线性问题。

SEVERAL PROBLEMS ON TYPE Ia SUPERNOVAE

First, statistical analysis on type Ia supernovae (hereafter SNe Ia) has been done by using Asiago Supernova Catalogue (ASC). Then SNe Ia with relatively precise photometry are congregated to investigate the homogeneity and heterogeneity with respect to peak luminosity. Spirals are more efficient SNe Ia producers, comparing with elliptical galaxies. It seems that the most luminous SNe Ia only occur in spiral galaxies, while both spiral and elliptical galaxies are hosts for dimmer SNe Ia. The spread of peak luminosity for SNe Ia located in the outer regions of galaxies is smaller, whereas such a trend disappears for blue SNe Ia. A straightforward color cut can be used to split SNe Ia into blue events and red ones. The former are relatively homogeneous SNe Ia subsample, which can serve as good extragalactic distance indicator; however, the existence of the latter indicates the diverse properties of SNe Ia as a whole. Finally, nonlinear process of carbon ignition is discussed.