论文标题
IA Supernova型SN 2020EYJ的核心退化场景
The core degenerate scenario for the type Ia supernova SN 2020eyj
论文作者
论文摘要
我们认为，IA型超新星（SNE IA）的核心退化（CD）场景可以解释SN 2020EYJ的紧凑型氦型且富含氦的且富含氦气的且富含氦气的情节。在CD方案的新渠道中，我们提出了两个主要的共同包膜演化（CEE）阶段。白矮人（WD）伴侣去除渐近巨型分支星的富含氢的包膜之后，其在几个太阳半径上从核心处停止了螺旋，而不是继续前往碳氧气（CO）核心，因为在富含氢的SNE IA-CSM CSM CD情况下。仅在氦富含氦气的核心扩展之后，仅数百到数万年后，WD才进入CEE，并带有富含氦气的层。到那时，富含氢的包膜距中心距离很大。 WD在第二个CEE阶段与CO核心合并，并且只有在合并爆炸延迟（MED）数周的时间到数十年的合并爆炸爆炸之后。 SN IA射出物与数十至数百个AU的富含氦的CSM相撞。当应该吞噬WD伴侣时，我们遵循两个恒星模型，其初始质量为5MO和7MO的渐近巨型分支阶段。我们发现，在CD场景的框架中，有足够的巨大CO核心与WD合并，以及〜0.3-1mo的巨大富含氦气层，以说明SN 2020EYJ的氦气富含CSM。
We argue that the core degenerate (CD) scenario of type Ia supernovae (SNe Ia) can explain the compact helium-rich circumstellar material (CSM) of SN 2020eyj. In the new channel of the CD scenario that we propose there are two major common envelope evolution (CEE) phases. After the white dwarf (WD) companion removes the hydrogen-rich envelope of the asymptotic giant branch star its spiralling-in halts at few solar radii from the core, rather than continuing to the carbon-oxygen (CO) core as in the hydrogen-rich SNe Ia-CSM CD scenario. Only hundreds to tens of thousands of years later, after the helium-rich core expands, does the WD enters a CEE with the helium-rich layer. By that time the hydrogen-rich envelope is at a large distance from the center. The WD merges with the CO core during the second CEE phase, and only after a merger to explosion delay (MED) time of weeks to tens of years the merger remnant explodes. The SN Ia ejecta collides with a helium-rich CSM at tens to hundreds of AU. We follow the evolution of two stellar models with initial masses of 5Mo and 7Mo to their asymptotic giant branch phase when they are supposed to engulf the WD companion. We find that there is a sufficiently massive CO core to merge with the WD in the frame of the CD scenario as well as a massive helium-rich layer, ~0.3-1Mo, to account for the helium-rich CSM of SN 2020eyj.
