论文标题
恒星合并M31-LRN-2015的尘土泥浆的祖先，前体和演变
Progenitor, Precursor and Evolution of the Dusty Remnant of the Stellar Merger M31-LRN-2015
论文作者
论文摘要
M31-2015-LRN可能是2015年在仙女座星系中发现的出色合并。我们为此事件提供了新的光学到中央光谱光度法和光学光谱。档案数据显示，源开始在Nova事件前2年开始亮起$ \ sim $ \ sim。在此前体阶段，来源通过$ \ sim $ 3 mag照亮。在主要爆发前6和1.5个月的灯泡可能显示周期性，分别为16 $ \ pm $ 0.3和28.1 $ \ pm $ 1.4天。这种复杂的发射可以通过在二进制经历Roche-Lobe溢出后系统的失控质量损失来解释，从而导致该系统在数十个轨道时期内结合。虽然祖细胞光谱能量分布没有显示系统中预先存在温暖灰尘的证据，但残留物在爆发峰后4个月以$ \ sim $ \ sim形成光学厚的灰尘壳。壳的光学深度在1。5年后急剧增加，这表明存在减轻灰尘形成过程的冲击。我们建议，合并残留物可能是一个充气巨人，被质量$ \ sim0.2 $ m $ _ {\ odot} $在公共信封阶段弹出的气体$ \ sim0.2 $ m $ _ {\ odot} $掩盖。
M31-2015-LRN is a likely stellar merger discovered in the Andromeda Galaxy in 2015. We present new optical to mid-infrared photometry and optical spectroscopy for this event. Archival data shows that the source started to brighten $\sim$2 years before the nova event. During this precursor phase, the source brightened by $\sim$3 mag. The lightcurve at 6 and 1.5 months before the main outburst may show periodicity, with periods of 16$\pm$0.3 and 28.1$\pm$1.4 days respectively. This complex emission may be explained by runaway mass loss from the system after the binary undergoes Roche-lobe overflow, leading the system to coalesce in tens of orbital periods. While the progenitor spectral energy distribution shows no evidence of pre-existing warm dust in system, the remnant forms an optically thick dust shell at $\sim$4 months after the outburst peak. The optical depth of the shell increases dramatically after 1.5 years, suggesting the existence of shocks that enhance the dust formation process. We propose that the merger remnant is likely an inflated giant obscured by a cooling shell of gas with mass $\sim0.2$ M$_{\odot}$ ejected at the onset of the common envelope phase.
