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.

该项目旨在分析将校准的可变恒星初始质量函数（IMF）应用到现代大规模流体动力学模拟中如何影响更广泛的星系特性。通用IMF固定了恒星群内的质量分布，与恒星形成的条件无关。这是星系形成模型中广泛接受的近似值，但最近对高质量早期型星系（ETG）的观测表明，与银河系相比，它们的质量光比过高。质光过剩 (MLE) 可以通过调整 IMF 来校正，以允许存在过多的低质量矮星（使 IMF 质量底部重）和/或恒星残余物（使 IMF 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。在星系形成模型中实现解释观测到的 MLE 的变量 IMF 将随后影响其他星系过程中的恒星反馈和恒星形成速率，这意味着必须更改模拟并自洽地运行，以便准确分析变量 IMF 可能如何影响星系的演化。为此，该项目将根据观测到的 MLE 关系校准变量 IMF，并分析将该 IMF 纳入最先进的流体动力学模拟如何影响星系特性。