超新星遗迹G1.9+0.3射电流量密度的时间演化

The Evolution of Radio Flux Densities of Supernova Remnant G1.9+0.3

对年轻超新星遗迹的射电观测有助于理解超新星遗迹的早期演化.选取银河系最年轻的超新星遗迹G1.9+0.3进行了研究.收集了已有的射电流量密度测量,转化到同一频率,从而获得了G1.9+0.3的流量密度在过去近50 yr的演化.发现流量密度在2008年之前几乎一直在增加,随后开始减小,流量密度达到峰值的年龄约为150-155 yr.流量密度的增加可能由磁场放大或者粒子加速效率提高产生的高能电子增多导致.根据流量密度到达峰值的年龄,结合前人的数值模拟,讨论了超新星抛射物的质量和超新星爆发释放的动能.

Radio observations of young supernova remnants(SNRs)can shed light on the early evolution of SNRs.We selected G1.9+0.3 which is the youngest SNRs in the Milky Way Galaxy for a study.We compiled the radio flux densities currently available and converted them to the same frequency,which leaves us the evolution of the flux densities for the past nearly 50 years.We found that the flux densities increase before 2008 and decrease afterwards,meaning the flux densities reaching the maximum at an age of about 150–155 yr.We attributed the brightening of the SNR to the increase of either magnetic field or the accelerated high energy electrons.Based on the age at which the flux density reached the peak,combined with the previous numerical simulation,we discussed the ejecta mass of the supernova and kinetic energy released by the supernova explosion.