千新星简介

An introduction to kilonovae

中子星-中子星或中子星-黑洞组成的致密双星系统在发生并合时,潮汐离心、碰撞挤压和吸积反馈等作用会导致约千分之几到百分之几倍太阳质量的物质被抛射到星际空间中。这些抛射物在加热机制的作用下可能达到较高的温度并快速膨胀,从而在紫外光学近红外波段发出一种快速变化的热辐射,即为千新星辐射。决定于抛射物的质量和不透明度,千新星的特征光变时标可估计在天到星期的量级。其辐射光度至少可达1041erg s-1的量级,具体决定于热源的性质,包括抛射物中通过快中子俘获过程形成的重元素的放射性衰变和并合产物可能的持续能量释放。千新星现象在2017年8月的GW170817引力波事件中被首次观测证实。

During the mergers o f neutron star-neutron star and neutron star-black hole binaries, about several thousandths to hundredths o f solar masses can be ejected outward due to the effects o f tidal centrifugation, collision squeeze, and accretion feedback. This ejected material can be heated to a high temperature to produce rapidly evolving thermal emission in the ultravioletoptical- infrared bands, which is called kilonova emission. The emission timescale o f a kilonova is from a few days to a few weeks, depending on the ejecta masses and opacities. The luminosity o f a kilonova can reach at least about 1041 erg s-1, which is specifically determined by the property of the heating sources including the radioactive decays o f r-process nuclei and the possible energy release from the merger products. The kilonova phenomena was first discovered and confirmed in the G W 170817 gravitational wave event.