论文标题
C，N，Si，Al和Ti的同位素比来自大型恒星的富含C的前晶粒
Isotopic ratios for C, N, Si, Al, and Ti in C-rich presolar grains from massive stars
论文作者
论文摘要
某些类型的碳化硅（SIC）晶粒，例如SIC-X晶粒和低密度（LD）石墨是富含C的前极晶粒，被认为在核心偏离的超新星（CCSNE）的射出中凝结了。在这项工作中，我们比较了在Presolar Grains中测得的C，N，AL，SI和Ti同位素丰度与21个CCSN模型的预测。考虑了一系列SN爆炸能量的影响，高能模型有利于形成C/Si区域，以$^{12} $ C，$^{28} $ SI和$^{44} $ TI。 21个型号中有18种摄入了he壳中的H壳和h含量不同的H ing-Engestion。具有中间至低能的CCSN模型（不开发C/SI区域）无法再现$^{28} $ SI和$^{44} $ ti同位素丰度，而无需假设与富含O-CCSN EXTEA混合。 The most $^{28}$Si-rich grains are reproduced by energetic models when material from the C/Si zone is mixed with surrounding C-rich material, and the observed trends of the $^{44}$Ti/$^{48}$Ti and $^{49}$Ti/$^{48}$Ti ratios are consistent with the C-rich C/Si zone.对于具有H ing的模型，高和中间的爆炸能量允许生产足够的$^{26} $ Al来重现大多数SIC-X和LD Graphites的$^{26} $ al/$^{27} $测量。在这两种情况下，最高的$^{26} $ al/$^{27} $ al比率均在$ x_h \ \ 0.0024 $中的HE壳材料中仍然存在，当时SN震动通过。 H中H的存在在前对流的He-Shell中指出了H-Ingestion的晚期事件，在大型恒星爆炸为超新星之前。
Certain types of silicon carbide (SiC) grains, e.g., SiC-X grains, and low density (LD) graphites are C-rich presolar grains that are thought to have condensed in the ejecta of core-collapse supernovae (CCSNe). In this work we compare C, N, Al, Si, and Ti isotopic abundances measured in presolar grains with the predictions of 21 CCSN models. The impact of a range of SN explosion energies is considered, with the high energy models favouring the formation of a C/Si zone enriched in $^{12}$C, $^{28}$Si, and $^{44}$Ti. Eighteen of the 21 models have H ingested into the He-shell and different abundances of H remaining from such H-ingestion. CCSN models with intermediate to low energy (that do not develop a C/Si zone) cannot reproduce the $^{28}$Si and $^{44}$Ti isotopic abundances in grains without assuming mixing with O-rich CCSN ejecta. The most $^{28}$Si-rich grains are reproduced by energetic models when material from the C/Si zone is mixed with surrounding C-rich material, and the observed trends of the $^{44}$Ti/$^{48}$Ti and $^{49}$Ti/$^{48}$Ti ratios are consistent with the C-rich C/Si zone. For the models with H-ingestion, high and intermediate explosion energies allow the production of enough $^{26}$Al to reproduce the $^{26}$Al/$^{27}$Al measurements of most SiC-X and LD graphites. In both cases, the highest $^{26}$Al/$^{27}$Al ratio is obtained with H still present at $X_H \approx 0.0024$ in He-shell material when the SN shock is passing. The existence of H in the former convective He-shell points to late H-ingestion events in the last days before massive stars explode as a supernova.
