General relativistic pulsations of ultra-massive ZZ Ceti stars
General relativistic pulsations of ultra-massive ZZ Ceti stars
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超大质量 ZZ 鲸鱼座恒星的广义相对论脉动
DOI：
10.1093/mnras/stad2248
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发表时间：
2023
影响因子：
4.8
通讯作者：
Torres, Santiago
中科院分区：
文献类型：
--
作者：
Córsico, Alejandro H.;Boston, S. Reece;Althaus, Leandro G.;Kilic, Mukremin;Kepler, S. O.;Camisassa, María E.;Torres, Santiago
得益于Gaiaspace使命等调查，目前超大质量白色矮星的发现速度相当快。这些致密致密的恒星残骸可能在Ia型超新星爆炸中发挥了重要作用。通过星震学可以探测超大质量白色矮星的内部。对于质量最大的白色矮星来说，广义相对论可能会对它们的结构和脉动产生实质性的影响。在这项工作中，我们提出的相对论脉动计算结果采用相对论超大质量ONe核白色矮模型与富氢的气氛和质量范围从1.29到目的是评估的绝热重力（g）模式周期谱的非常高质量的ZZ鲸鱼座恒星的广义相对论的影响。采用相对论Cowling近似的脉动分析，我们发现，临界浮力（Brunt-Väisälä）和声学（Lamb）频率较大的相对论的情况下，相比牛顿的情况下，由于相对论白色矮星模型具有较小的半径和较高的重力为一个固定的恒星质量。此外，g模式周期在相对论情况下比在牛顿计算中短，对于最高质量模型（）和典型的ZZ Ceti不稳定带的有效温度，相对差异高达10%。因此，广义相对论对质量大于1000的白色矮星的结构、演化和脉动的影响在对超大质量鲸鱼座ZZ星的星震学分析中不可忽视。
Ultra-massive white dwarf stars are currently being discovered at a considerable rate, thanks to surveys such as theGaiaspace mission. These dense and compact stellar remnants likely play a major role in Type Ia supernova explosions. It is possible to probe the interiors of ultra-massive white dwarfs through asteroseismology. In the case of the most massive white dwarfs, general relativity could affect their structure and pulsations substantially. In this work, we present results of relativistic pulsation calculations employing relativistic ultra-massive ONe-core white dwarf models with hydrogen-rich atmospheres and masses ranging from 1.29 towith the aim of assessing the impact of general relativity on the adiabatic gravity (g)-mode period spectrum of very high mass ZZ Ceti stars. Employing the relativistic Cowling approximation for the pulsation analysis, we find that the critical buoyancy (Brunt–Väisälä) and acoustic (Lamb) frequencies are larger for the relativistic case, compared to the Newtonian case, due to the relativistic white dwarf models having smaller radii and higher gravities for a fixed stellar mass. In addition, theg-mode periods are shorter in the relativistic case than those in the Newtonian computations, with relative differences of up to ∼per cent for the highest mass models () and for effective temperatures typical of the ZZ Ceti instability strip. Hence, the effects of general relativity on the structure, evolution, and pulsations of white dwarfs with masses larger than ∼cannot be ignored in the asteroseismological analysis of ultra-massive ZZ Ceti stars.