AI 中文总结
该研究利用ASKAP的VAST巡天数据，对43颗经典新星的射电辐射进行搜寻，发现3颗存在显著射电辐射，通过单频射电光变曲线结合物理模型，证实其以非热同步辐射为主，为激波驱动粒子加速提供证据。
AI 中文摘要
我们利用澳大利亚平方公里阵列探路者（ASKAP）变源与慢暂现源（VAST）巡天的数据，开展了887.5 MHz频率下经典新星的射电辐射搜寻工作。我们在1200平方度的银道面巡天天区内，交叉匹配了43颗2021年9月至2025年11月间爆发的光学发现的经典新星，发现其中3颗存在显著的射电辐射：V6598 Sgr、V1716 Sco和V1723 Sco。为分析它们的射电光变曲线，我们同时采用了热轫致辐射和非热同步辐射模型；我们使用马尔可夫链蒙特卡罗（MCMC）方法拟合数据，以约束相关参数，包括热模型中的抛射物质量和抛射物速度，以及非热模型中的质量损失率、爆发能量、风速度和填充因子。这3颗新星均显示出非热同步辐射作为该频率下主导辐射机制的证据。我们采用断裂幂律来描述非均匀双星周际物质的径向密度结构，该结构比标准风密度剖面能提供更优的拟合结果。这种强烈的早期同步辐射是激波驱动粒子加速的有力证据，这也可能与这3颗新星的伽马射线探测相关。与此前使用多频数据区分辐射模型的研究不同，我们的分析基于单频射电光变曲线，当结合具有物理动机的模型进行解释时，仍能对主导辐射机制提供有用的约束。
英文摘要
We present a search for radio emission from classical novae at 887.5 MHz using data from the Australian SKA Pathfinder Variable And Slow Transient (VAST) survey. We cross-matched 43 optically discovered classical novae that erupted between 2021 September and 2025 November within the 1200-square-degree Galactic survey footprint, and found three which show significant radio emission: V6598 Sgr, V1716 Sco, and V1723 Sco. To analyse their radio light curves, we use both thermal free-free and non-thermal synchrotron emission models. We fit the data using the Markov chain Monte Carlo (MCMC) method to constrain parameters, including the ejected mass and ejecta velocities for the thermal models, and mass-loss rate, explosion energy, wind velocity, and filling factor for the non-thermal model. All three novae show evidence of non-thermal synchrotron emission as the dominant emission mechanism at this frequency. We use a broken power law to describe the radial density structure of a non-uniform circumbinary material, which provides a better fit than a standard wind density profile. This strong early-time synchrotron emission is strong evidence of shock-driven particle acceleration, which may be related to detections of gamma-rays from all three novae as well. In contrast to earlier studies that used multi-frequency data to distinguish between emission models, our analysis is based on single-frequency radio light curves, which can still provide useful constraints on the dominant emission mechanism when interpreted with physically motivated models
CommentsAccepted for publication in Publications of the Astronomical Society of Australia (PASA)
