Searching for the next Galactic Luminous red nova
Searching for the next Galactic Luminous red nova
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寻找下一颗银河发光红色新星
DOI：
10.1093/mnras/stac2685
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发表时间：
2022
影响因子：
4.8
通讯作者：
Addison H
中科院分区：
文献类型：
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作者：
Addison H
发光红新星（LRNe）是一种天体物理学上的瞬变现象，被认为是由双星星星的共同包层（CE）的部分抛射及其成分的合并引起的。CE的形成很可能发生在不稳定的质量转移过程中，由一星星正在脱离主序星（赫兹弹簧间隙星星）和一颗质量较低的伴星引发。与观测结果一致，理论研究表明，前CE阶段的流出物在喷射事件发生前几年产生了可检测到的祖系统增亮。基于这些假设，我们提出了一种方法来识别银河系LRNe的前体，由此产生的前体候选人，我们的后续分析，以揭示其性质。我们开始通过构建一个样本的祖系统，即赫兹差距的明星，通过统计建模的颜色星等图形成的“表现良好”的盖亚DR 2源的密度。他们的时域演变从Zwicky瞬变设施（ZTF）的调查是用来寻找缓慢增亮的事件，作为前CE的前兆候选人。使用档案数据和我们自己的光谱跟踪进一步研究所产生的候选人的性质。总的来说，我们构建了一个约5.4 × 104个原始源的样本，其中21个被确定为候选LRNe前体。进一步的分析显示，我们的候选者中有16颗是Hα发射体，它们的光谱通常表明它们是较热的（尽管是中等偏热的）A型或B型恒星。由于他们的长期变化，在光学和中红外波长，我们建议，我们的许多候选人是质量转移的双星与紧密的同伴周围的尘埃拱盘或磁活跃的恒星合并残余物。
Luminous red novae (LRNe) are astrophysical transients believed to be caused by the partial ejection of a binary star’s common envelope (CE) and the merger of its components. The formation of the CE is likely to occur during unstable mass transfer, initiated by a primary star which is evolving off the main sequence (a Hertzsprung gap star) and a lower mass companion. In agreement with observations, theoretical studies have shown that outflows from the pre-CE phase produce a detectable brightening of the progenitor system a few years before the ejection event. Based on these assumptions, we present a method to identify Galactic LRNe precursors, the resulting precursor candidates, and our follow-up analysis to uncover their nature. We begin by constructing a sample of progenitor systems, i.e. Hertzsprung gap stars, by statistically modelling the density of a colour magnitude diagram formed from ‘well behaved’ Gaia DR2 sources. Their time-domain evolution from the Zwicky Transient Facility (ZTF) survey is used to search for slowly brightening events, as pre-CE precursor candidates. The nature of the resulting candidates is further investigated using archival data and our own spectroscopic follow-up. Overall, we constructed a sample of ∼5.4 × 104progenitor sources, from which 21 were identified as candidate LRNe precursors. Further analysis revealed 16 of our candidates to be Hα emitters, with their spectra often suggesting hotter (albeit moderately extincted) A-type or B-type stars. Because of their long-term variability in optical and mid-infrared wavelengths, we propose that many of our candidates are mass-transferring binaries with compact companions surrounded by dusty circumstellar discs or alternatively magnetically active stellar merger remnants.