快速旋转磁陀星驱动的类超新星现象研究概述

Brief review of the study of supernova-like phenomena driven by rapidly rotating magnetars

一颗快速旋转的高度磁化中子星(磁陀星)可能诞生于极端的恒星爆发或双致密星并合等过程.这一理论设想在近二十余年的伽马射线暴研究中常被提及且已受到诸多观测尤其是余辉观测的支持.因此,该新生磁陀星与这些爆发或并合产生的抛射物之间的相互作用及其产生的观测特征引起了人们的广泛关注.与此同时,近十余年来,随着宽视场高频次暂现源巡天项目的大量开展,人们陆续发现了为数不少的具有和普通超新星相似特征但又存在明显差异的光学暂现源现象,其典型代表有以高光度为主要特征的超亮超新星和以快速演化为主要特征的快变蓝色暂现源.这些现象为研究新生磁陀星驱动的类超新星爆发和辐射过程提供了现实途径.本文一方面概述了中子星的能量输出、中子星风和抛射物的相互作用及相应的辐射效应,主要包括抛射物热辐射主峰的增亮、主峰前由中子星风驱动的激波突破以及主峰后星风云非热辐射的泄漏等.另一方面,简要介绍了超亮超新星、伽马射线暴及其成协超新星或并合新星、快变蓝色暂现源等现象的主要观测特征,着重讨论了这些观测现象和中子星能源模型之间的相容性,以及模型和观测相结合所给出的参数限制.据此,可以更进一步地了解在相同的物理机制下产生不同观测现象的关键因素以及潜藏在观测差异背后的可能统一性.

A rapidly rotating and highly magnetized neutron star(magnetar)may be formed during extreme stellar explosions or binary compact star mergers.Over the past two decades,this theoretical hypothesis has been widely investigated in studies on gamma-ray bursts(GRBs)and has been supported by numerous observations,particularly those related to afterglow emissions.Therefore,the interaction between such a newborn magnetar and the ejecta produced because of explosions or mergers needs to be elucidated in theory to predict possible observational signatures.Meanwhile,in observations,a considerable number of optical transients have been discovered in the past decades through various high-cadence transient surveys,which are generally analogous to ordinary supernovae but distinct in their luminosity or timescales.Two representative phenomena are superluminous supernovae(SLSNe)and fast blue optical transients(FBOTs).These phenomena,including the aforementioned GRBs,provide a realistic path for analyzing magnetar-driven explosions and the corresponding radiation processes.On the one hand,this review summarizes the primary influences of a newborn magnetar on explosion radiation,including the enhancement of the thermal radiation of ejecta,shock breakout driven by the magnetar wind,and leakage of nonthermal radiation from pulsar wind nebula.On the other hand,the main observational results of SLSNe,GRBs and their associated supernovae or mergernovae,and FBOTs are briefly introduced,focusing on the consistency between the observations and the magnetar engine model,as well as the observational constraints on the model parameters.Finally,the possible unified origin of different phenomena and the reasons leading to the differences are discussed.