arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2211.04777astro-ph.GA
收藏

超新星遗迹仙后座A射电结的研究

A Study of Radio Knots within Supernova Remnant Cassiopeia A

Xianhuan Lei, Hui Zhu, Haiyan Zhang, Wenwu Tian

摘要:

研究年轻超新星遗迹的动力学演化是了解其前身星周介质密度结构的重要途径。利用1987 ~ 2004年5个历元的VLA观测资料,报道了5..GHz信噪比第二年轻的Cas A中260个致密射电特征的加减速、自行和亮度变化。无线电扩展中心位于$α(1950)=23^{\rm h}21^{\rm m}9^{\rm s}_{\cdot}7 \pm 0^{\rm s}_{\cdot}29, δ(1950)=+58^{\circ}32^{\prime}25^{\prime\prime}_{\cdot}2 \pm 2^{\prime\prime}_{\cdot}2$。四分之三的致密结正在减速,这表明在残余物的祖先的恒星风中有显着的密度波动。我们已经证实,致密结的加速或减速与亮度分布无关。Cas A中致密射电特征的增亮、减弱、消失或新出现表明残骸中的磁场正在迅速变化。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑