标题： 通过盘不稳定性形成的隆起 -- 第一章 显示英文标题

标题： Bulge formation through disc instability -- I

摘要： 我们使用数值模拟研究嵌入静态球形晕轮中的孤立薄指数恒星盘中伪核仁的增长。我们观察到从后期到早期形态类型的转变，并且对于更高的盘与晕的质量比、更低的盘与晕的尺寸比以及更低的晕集中度，棒的显著性增加。我们通过拟合双成分Sérsic-指数表面密度分布来计算核仁与总恒星质量比 $B/T$。最终的 $B/T$ 与盘在光学半径处对总引力加速度的分数贡献 $f_{\rm d}$ 密切相关。公式 $B/T=0.5\,f_{\rm }^{1.8}$ 准确度达到 $30\%$ 拟合了模拟结果，与观测测量值B/T和f_d随光度变化一致，并且当将其纳入GalICS~2.0 星系形成半解析模型时，再现了观测到的 $B/T$ 和恒星质量之间的关系。 显示英文摘要

摘要： We use simulations to study the growth of a pseudobulge in an isolated thin exponential stellar disc embedded in a static spherical halo. We observe a transition from later to earlier morphological types and an increase in bar prominence for higher disc-to-halo mass ratios, for lower disc-to-halo size ratios, and for lower halo concentrations. We compute bulge-to-total stellar mass ratios $B/T$ by fitting a two-component S\'ersic-exponential surface-density distribution. The final $B/T$ is strongly related to the disc's fractional contribution $f_{\rm d}$ to the total gravitational acceleration at the optical radius. The formula $B/T=0.5\,f_{\rm }^{1.8}$ fits the simulations to an accuracy of $30\%$, is consistent with observational measurements of B/T and f_d as a function of luminosity, and reproduces the observed relation between $B/T$ and stellar mass when incorporated into the GalICS~2.0 semi-analytic model of galaxy formation.