发表机构
Korea Astronomy and Space Science Institute; Department of Astronomy and Space Science, University of Science and Technology（韩国天文与空间科学研究院; 科学技术大学天文与空间科学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究利用时域TransRAT框架预测IIP型超新星照亮的致密云的尘埃偏振，识别出偏振耀斑等四个关键特征，还发现超新星诱导的偏振特性在远处会留下化石印记，为近期观测测试提供依据。
AI 中文摘要
宇宙瞬变可以在几天到几个月的时间尺度上显著增强局部辐射场。使用时域TransRAT框架，该框架自洽地演化颗粒加热、排列、旋转破坏以及磁场（B-RAT）和辐射方向（k-RAT）之间排列轴的切换，我们预测了不同距离处IIP型超新星照亮的致密云的随时间变化的尘埃偏振。我们识别出四个关键特征。首先，对于\(D\lesssim1\) pc，在几天到几周内会出现偏振耀斑，其特征是热尘埃偏振和消光偏振效率急剧增加；随后是偏振下降，因为辐射扭矩破坏（RAT-D）会破坏大的排列颗粒。其次，随着最小排列颗粒尺寸减小，消光偏振的峰值波长\(\lambda_{\rm max}\)向蓝移，这提供了一种很大程度上独立于磁场几何形状的诊断方法。第三，在我们的基准几何形状中，从B-RAT到k-RAT的转变会产生\(45^{\circ}\)的突然偏振角旋转。第四，随着瞬变消退，回到B-RAT会产生由拉莫尔进动控制的偏振角混响。这种混响是颗粒磁性最敏感的探测器，超顺磁性颗粒比顺磁性颗粒恢复得更快。在\(D>1\) pc时，超新星诱导的偏振特性在辐射消退后会持续很长时间，留下化石印记。这种印记提供了最实际的近期观测测试：年龄小于约\(10\,t_{\rm gas}\)（\(t_{\rm gas}\)为气体阻尼时间）弛豫时间尺度的超新星遗迹附近的云，今天应该表现出增强的偏振和蓝移的\(\lambda_{\rm max}\)。
英文摘要
Cosmic transients can enhance the local radiation field on timescales of days to months. Using the time-domain \TransRAT\ framework, which self-consistently follows grain heating, alignment, rotational disruption, and switching of the alignment axis between the magnetic field ({\bf B}) and the radiation direction ({\bf k}), we predict the time-dependent dust polarization of a dense cloud, represented by a homogeneous one-zone model, illuminated by a Type~IIP supernova over a range of source--cloud distances. We identify four key signatures. First, for $D\lesssim1$~pc, a \emph{polarization flare} develops within days to weeks, marked by sharp increases in both thermal dust polarization and extinction-polarization efficiency; this is followed by a \emph{polarization dip} as radiative torque disruption (RAT-D) destroys the large aligned grains. Second, the peak wavelength of extinction polarization, $λ_{\rm max}$, shifts blueward as the minimum aligned-grain size decreases. Third, the transition from B-RAT to k-RAT produces an abrupt \emph{polarization-angle rotation} of up to $45^{\circ}$ in our fiducial geometry. Fourth, as the transient fades, the return to B-RAT generates a \emph{polarization-angle reverberation} governed by Larmor precession. At $D>1$~pc, SN-induced polarization properties can persist long after the radiation has faded. These {\it fossil imprints} offer the most practical near-term observational test: clouds near supernova remnants younger than the relaxation timescale of $\sim10\,t_{\rm gas}$ with $t_{\rm gas}$ gas damping time, should exhibit elevated polarization and blueshifted $λ_{\max}$ today. Time-dependent dust polarization can therefore probe dust physics, dust properties, and pristine pre-shock magnetic fields in real time, while fossil imprints preserve a record of past explosions.
Comments12 pages, 6 figures; minor revisions
