发表机构
University of Turku; Niels Bohr Institute, University of Copenhagen; European University Cyprus; Queen’s University Belfast; INAF – Osservatorio Astronomico di Padova; INAF – Osservatorio Astronomico di Brera; Yunnan Observatories, Chinese Academy of Sciences (CAS)（图尔库大学; 哥本哈根大学尼尔斯·玻尔研究所; 塞浦路斯欧洲大学; 贝尔法斯特女王大学; 意大利国家天体物理研究所帕多瓦天文台; 意大利国家天体物理研究所布雷拉天文台; 中国科学院云南天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究报道了三颗在发光红外星系NGC6745中心爆发的核心坍缩超新星，通过分光光度观测表征其演化、消光及物理性质，并利用SED建模估算星暴年龄与超新星率，揭示了SN2009ip-like事件及快速演化的IIb型超新星特征。
AI 中文摘要
核心坍缩超新星（CCSNe）2022prr、2023ucy和2024ljc在邻近的发光红外星系（LIRG）NGC6745的中心区域爆发。我们展示了后续观测数据，旨在表征这些CCSNe的分光光度演化，确定其宿主星系消光，并界定其物理性质。所展示的分光光度数据集覆盖了我们三颗超新星（SNe）的光学和近红外波段。这些数据被分析并与其它富氢CCSNe进行比较，并基于每个目标的光度测光推导出宿主星系消光值Av。构建了宿主星系的谱能量分布（SED），并将不同的星系成分组合拟合到SED上，以估算NGC6745的内在CCSN率及星暴年龄。2022prr是一个SN2009ip-like事件，其光变曲线演化由两个连续的光度事件A和B组成，峰值星等分别为Mr = -14.8和-18.3等。在最大光附近的高V和R波段偏振度（P=2.8%）表明与高度非球形的星周物质相互作用。该SN的光谱演化以窄的巴耳末发射线为主，这些发射线随时间有复杂的演化。2022prr加入了日益增多的SN2009ip-like事件样本，这些事件显示出早期的CIII、NIII和HeII的“闪光电离”特征。2023ucy被发现是一个正常的IIP型SN。然而，2024ljc是一个快速演化的IIb型SN，其峰值后r波段衰减在+41天时约为3.2星等，而正常的IIb型SN在相同时间尺度内通常衰减1.5±0.3星等。尽管这些事件在LIRG中爆发，但SNe仅受到中等程度的V波段宿主消光，范围从0到1星等。基于SED建模，我们估计宿主星暴年龄为40Myr，内在CCSN率为0.4±0.1 SN/年。
英文摘要
The core-collapse supernovae (CCSNe) 2022prr, 2023ucy, and 2024ljc exploded within the central regions of the nearby luminous infrared galaxy (LIRG) NGC6745. We present our follow-up data with the aim to characterise the spectrophotometric evolution of these CCSNe, determine their host-galaxy extinction, and to define their physical nature. The presented spectrophotometric data set covers the optical and near-infrared region for our three supernovae (SNe). The data are analysed and compared to other hydrogen-rich CCSNe, and a host-galaxy extinction value Av is derived based on broadband photometry for each of the targets. A spectral energy distribution (SED) for the host galaxy is constructed, and a combination of different galactic components are fitted to the SED to estimate the intrinsic CCSN rate and the age of the starburst of NGC6745. 2022prr is a SN2009ip-like event, whose light curve evolution consists of two consecutive luminous events A and B with peak magnitudes of Mr = -14.8 and -18.3 mag, respectively. The high degree of V and R-band polarisation (P=2.8%) near maximum light suggests interaction with highly aspherical circumstellar material. The spectral evolution of the SN is dominated by narrow Balmer emission lines, which have a complex evolution over time. 2022prr joins the growing sample of SN2009ip-like events that show early `flash ionisation' features of CIII, NIII, and HeII. 2023ucy is found to be a normal Type IIP SN. However, 2024ljc is a rapidly evolving Type IIb SN with a post-maximum r-band decline of roughly 3.2 mag by +41 d whereas normal IIb SNe decline typically by 1.5+/-0.3 mag during the same timescale. While the events exploded in a LIRG, the SNe are obscured by only moderate V-band host extinctions ranging from 0 to 1 mag. Based on the SED modelling we estimate an age of the host starburst to be 40Myr, and the intrinsic CCSN rate to be 0.4+/-0.1 SN/year.
