论文标题
比较两个几乎相等质量祖细胞的核心折断演变
Comparison of the Core-Collapse Evolution of Two Nearly Equal Mass Progenitors
论文作者
论文摘要
我们比较了一对15.8 $ m_ \ odot $ stars具有明显不同的内部结构的核心折叠演变，这是大型恒星在其后期进化阶段表现出的双峰变异性的结果。 15.78和15.79 $ m_ \ odot $祖先的核心质量为1.47和1.78 $ m_ \ odot $和紧凑型参数$ξ_{1.75} $ 0.302和0.604。核心崩溃模拟在2D上进行到近3次，并在冲击复兴和爆炸能量时显示出很大的差异。 15.78 $ m_ \ odot $型号在弹跳后120毫秒时迅速爆炸时，当Sii-Si/O shell接口处强度降低时，遇到停滞的冲击。缺乏密度降低的15.79 $ m_ \ odot $模型需要爆炸时间更长100毫秒，但最终会产生更强大的爆炸。 15.79 $ M_ \ odot $模型的较大质量积聚率在第一个0.8 s后弹跳中导致较大$ν_{e} $/$ \barν_{e} $ Luminosities和RMS Energies。由于较大的绝热压力，由于该核心的较大的负温度梯度，因此$/$ \ bar bbarν_{e} $ Luminosities和由内核产生的RMS能量也更大。在15.79 $ m_ \ odot $模型中，较大的亮度和RMS能量和更高的密度加热区域，导致冲击背后的能量沉积更多，并且更高的物质具有更高的焓。我们发现15.79 $ m_ \ odot $型号的弹出$^{56} $ ni质量是15.78 $ m_ \ odot $型号的两倍以上。这两种模型中的大多数弹射量都适中富含质子，尽管在任何模型中，违反直觉的电子分数（$ y_e = 0.61 $）的弹出ejecta在不太能量的15.78 $ m_ \ odot $模型中，而最低的电子分数（$ y_e = 0.45 $）在两种模型中是15.79 $ __________________________________________ $ f f。
We compare the core-collapse evolution of a pair of 15.8 $M_\odot$ stars with significantly different internal structures, a consequence of bimodal variability exhibited by massive stars during their late evolutionary stages. The 15.78 and 15.79 $M_\odot $ progenitors have core masses of 1.47 and 1.78 $M_\odot$ and compactness parameters $ξ_{1.75}$ of 0.302 and 0.604. The core collapse simulations are carried out in 2D to nearly 3 s post-bounce and show substantial differences in the times of shock revival and explosion energies. The 15.78 $M_\odot$ model explodes promptly at 120 ms post-bounce when a strong density decrement at the Si--Si/O shell interface encounters the stalled shock. The 15.79 $M_\odot$ model, which lacks the density decrement, takes 100 ms longer to explode but ultimately produces a more powerful explosion. Larger mass accretion rate of the 15.79 $M_\odot$ model during the first 0.8 s post-bounce results in larger $ν_{e}$/$\bar ν_{e}$ luminosities and rms energies. The $ν_{e}$/$\bar ν_{e}$ luminosities and rms energies arising from the inner core are also larger in the 15.79 $M_\odot$ model throughout due to the larger negative temperature gradient of this core due to greater adiabatic compression. Larger luminosities and rms energies in the 15.79 $M_\odot$ model and a flatter and higher density heating region, result in more energy deposition behind the shock and more ejected matter with higher enthalpy. We find the ejected $^{56}$Ni mass of the 15.79 $M_\odot$ model is more than double that of the 15.78 $M_\odot$ model. Most of the ejecta in both models is moderately proton-rich, though counterintuitively the highest electron fraction ($Y_e=0.61$) ejecta in either model is in the less energetic 15.78 $M_\odot$ model while the lowest electron fraction ($Y_e=0.45$) ejecta in either model is in the 15.79 $M_\odot$ model.
