7.This and the X-ray spectrum, which exhibits a high concentration of iron atoms relative to oxygen and silicon, convincingly show that the ejecta are the remains of an exploded white dwarf star.

• 这幅图连带X射线光谱（显示出了铁相对氧与硅的高度集中）令人信服地说明，抛出的物质是爆发白矮星的残余。