超新星SN 1987A的热光度演化──内部中子星的贡献

本文介绍了超新星SN1987A爆发六年多来其热光度演化的研究情况．爆发后的前800天，观测的热光度曲线与由超新星爆发时合成的放射性元素的放射衰变加热模型符合得很好．但900天以后，观测的热光度曲线比考虑了所有放射性元素贡献后的理论曲线下降得还要缓慢．这可能表明有新的能源在起作用．我们认为这个新的能源可能是超新星爆发时产生的中子星的吸积．通过吸积超新星爆发时抛射气壳中小于逃逸速度的部分物质而增大SN1987A的热光度．这一模型能很好地解释900天以后的光度曲线的下降变级以及900至1200天之间光度曲线的凸起，这也为内部中子星的存在提供了间接的证据．

SN1987A: Evolution of the Bolometric Light Curve Contribution of the Central Neutron Star

We present a study of the bolometric light curve of SN1987A. The bolometric luminosity evolution through day 8Oo has followed extremely well the early theoretical predictions by setting the energy input from radioactive decay of ~ 0.07M56Co. But after day 900,the bolometric luminosity decline began to slow down and the bolometric light curve was flatter than theoretical predictions; between day 900 and day 1200, the bolometric light curve exhibited a significant flattening. This bump has been known for some time, but the problem of its origin has scarcely beell addressed theoretically. Wu suggest that the decay of the radioactive materials alone cannot supply enough energy to power the luminosity of SN1987A after day 900. It is more likely that the central neutron star could be an energy source, and the most likely radiation mechanism is accretion. By accreting the matter whose expanding velocity is lower than the escaping velocity, the celltral neutron star can supply enough additional energy to produce the observed bump and flattening of the bolometric light curve after day 900.