Cosmological hydrodynamical simulations with calibrated non-universal initial mass functions

使用校准的非通用初始质量函数进行宇宙流体动力学模拟

• 批准号: 2903298
• 金额: --
• 依托单位: Liverpool John Moores University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2027
• 资助国家: 英国
• 起止时间: 2027 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2903298
• 关键词: Cosmological; hydrodynamical; simulations; calibrated; non

This project aims to analyse how implementing a calibrated variable stellar initial mass function (IMF) into a modern large-scale hydrodynamical simulation affects wider galactic properties. A universal IMF fixes the distribution of mass within a stellar population independent of the conditions under which the stars formed. This is a widely accepted approximation in galaxy formation models, but recent observations of high-mass early-type galaxies (ETGs) indicate excesses in their mass-to-light ratios in comparison to the Milky Way. The mass-to-light excess (MLE) can be corrected by adapting the IMF to allow an overabundance of low-mass dwarf stars (making the IMF bottom-heavy in mass) and/ or stellar remnants (making the IMF top-heavy) such that the mass in stars in ETGs is increased without altering the luminosity of the stars. Implementing a variable IMF that explains the observed MLE into a galaxy formation model will subsequently affect stellar feedback and stellar formation rates among other galactic processes, meaning that simulations must be altered and run self-consistently in order to accurately analyse how a variable IMF may affect the evolution of galaxies. To this end, this project will calibrate a variable IMF based on observed MLE relations and analyse how incorporating this IMF into a state-of-the-art hydrodynamical simulation affects galaxy properties.

该项目旨在分析如何将校准的可变恒星初始质量函数（IMF）应用于现代大尺度流体动力学模拟，从而影响更广泛的银河系性质。一个普遍的IMF确定了恒星群体内的质量分布，而与恒星形成的条件无关。这在星系形成模型中是一个被广泛接受的近似值，但最近对高质量早型星系（ETG）的观测表明，与银河系相比，它们的质光比过大。质轻过剩（MLE）可以通过调整IMF来修正，以允许过多的低质量矮星（使IMF的质量底部重）和/或恒星残留物（使IMF的顶部重），这样ETG中恒星的质量就会增加而不会改变恒星的光度。实施一个变量IMF，解释所观察到的MLE到星系形成模型将随后影响恒星反馈和恒星形成率之间的其他星系过程，这意味着模拟必须改变和运行自洽，以准确地分析如何变量IMF可能会影响星系的演化。为此，该项目将根据观察到的MLE关系校准变量IMF，并分析如何将此IMF纳入最先进的流体动力学模拟影响星系特性。