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; 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在现代的大规模流体动力学模拟中实现校准的恒星初始质量功能（IMF）如何影响更广泛的银河系。通用IMF固定在恒星种群中质量的分布，而与恒星形成的条件无关。这是银河形成模型中广泛接受的近似值，但是最近对高质量早期型星系（ETG）的观察表明，与银河系相比，其质量与光的比率过高。可以通过适应IMF来纠正质量到光的过量（MLE），以使低质量矮人的恒星（使IMF质量较重）和/或出色的残留物（使IMF较重）（使IMF最高量）（使ETG中的恒星中的质量都会增加，而不会改变星星的光度。实施可变的IMF，将观察到的MLE解释为银河形成模型，随后将影响其他银河系过程中的恒星反馈和恒星形成率，这意味着必须改变模拟并自愿进行模拟，以便准确地分析可变IMF如何影响星系的演化。为此，该项目将基于观察到的MLE关系校准IMF，并分析将此IMF纳入最先进的流体动力学模拟会影响星系特性。