论文标题
对超新星残余cassiopeia中无线电结的研究
A Study of Radio Knots within Supernova Remnant Cassiopeia A
论文作者
论文摘要
关于年轻超新星残留物（SNR）动态演变的研究是了解祖细胞偶然培养基的密度结构的重要方法。我们已经根据1987年至2004年的五个时期的VLA数据，在第二个最年轻的SNR CAS A中报告了260个紧凑型无线电特征的加速度或减速，适当的运动和亮度变化。无线电扩展中心位于$α（1950）（1950）= 23^^{\ rm h} 21^21^21^{\ rmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm { s} _ {\ cdot} 7 \ pm 0^{\ rm s} _ {\ cdot} 29，δ（1950）=+58^{\ crock} 32^{\ prime} 25^{\ prime \ prime \ prime \ prime \ prime} 2^{\ prime \ prime} _ {\ cdot} 2 $。紧凑结的四分之三正在减速，这表明残留物祖细胞的恒星风发生了明显的密度波动。我们已经验证了紧凑结的加速或减速与亮度的分布无关。 CAS A中紧凑的无线电特征的亮，褪色，消失或新出现表明，残留物中的磁场正在迅速变化。
The study on the dynamic evolution of young supernova remnants (SNRs) is an important way to understand the density structure of the progenitor's circumstellar medium. We have reported the acceleration or deceleration, proper motion and brightness changes of 260 compact radio features in the second youngest known SNR Cas A at 5\,GHz based on the VLA data of five epochs from 1987 to 2004. The radio expansion center locates at $α(1950)=23^{\rm h}21^{\rm m}9^{\rm s}_{\cdot}7 \pm 0^{\rm s}_{\cdot}29, δ(1950)=+58^{\circ}32^{\prime}25^{\prime\prime}_{\cdot}2 \pm 2^{\prime\prime}_{\cdot}2$. Three-quarters of the compact knots are decelerating, this suggests that there are significant density fluctuations in the stellar winds of the remnant's progenitor. We have verified that the acceleration or deceleration of compact knots are not related with the distribution of brightness. The brightening, fading, disappearing or new appearing of compact radio features in Cas A suggests that the magnetic field in the remnant is changing rapidly.
