论文标题
超质量白矮星星星学的新的全面进化模型
New fully evolutionary models for asteroseismology of ultra-massive white dwarf stars
论文作者
论文摘要
Ultra-massive hydrogen-rich (DA spectral type) white dwarf (WD) stars ($M_{\star} > 1M_{\odot}$) coming from single-star evolution are expected to harbor cores made of $^{16}$O and $^{20}$Ne, resulting from semi-degenerate carbon burning when the progenitor star evolves through the super asymptotic giant分支（S-AGB）阶段。预计这些恒星将在到达ZZ CETI不稳定条带的时间（$ t _ {\ rm eff} \ sim 12 \，500 $ k）。理论模型预测，结晶会导致$^{16} $ o和$^{20} $ ne的分离，这会影响其脉动属性。该属性提供了研究结晶过程的独特机会。在这里，我们介绍了对最详细的超质量ZZ CETI星BPM 〜37093进行详细的呼吸震学分析的结果。作为第二步，我们计划使用具有C/O核心的超质量DA WD模型重复此分析，以研究阐明BPM 〜37093的核心化学成分的可能性，并阐明了其可能的进化起源。我们还计划将这种分析扩展到从地面观察到的其他恒星，以及从开普勒和苔丝等太空任务中观察到的。
Ultra-massive hydrogen-rich (DA spectral type) white dwarf (WD) stars ($M_{\star} > 1M_{\odot}$) coming from single-star evolution are expected to harbor cores made of $^{16}$O and $^{20}$Ne, resulting from semi-degenerate carbon burning when the progenitor star evolves through the super asymptotic giant branch (S-AGB) phase. These stars are expected to be crystallized by the time they reach the ZZ Ceti instability strip ($T_{\rm eff} \sim 12\,500$ K). Theoretical models predict that crystallization leads to a separation of $^{16}$O and $^{20}$Ne in the core of ultra-massive WDs, which impacts their pulsational properties. This property offers a unique opportunity to study the processes of crystallization. Here, we present the first results of a detailed asteroseismic analysis of the best-studied ultra-massive ZZ Ceti star BPM~37093. As a second step, we plan to repeat this analysis using ultra-massive DA WD models with C/O cores in order to study the possibility of elucidating the core chemical composition of BPM~37093 and shed some light on its possible evolutionary origin. We also plan to extend this kind of analyses to other stars observed from the ground and also from space missions like Kepler and TESS.
