Calibrated, cosmological hydrodynamical simulations with variable IMFs I: Method and effect on global galaxy scaling relations
Christopher Barber, Robert A. Crain, Joop Schaye
备注：
23 pages, 13 figures (+ 6 pages, 6 figures of appendices). Accepted for publication in MNRAS. Simulation data will become publicly available upon publication. Relative to the previous version, we now include comparisons to the observed dwarf-to-giant ratios and ionizing flux in ETGs and star-forming galaxies, respectively
The recently inferred variations in the stellar initial mass function (IMF) among local high-mass early-type galaxies may require a reinterpretation of observations of galaxy populations and may have important consequences for the predictions of models of galaxy formation and evolution. We present a new pair of cosmological, hydrodynamical simulations based on the EAGLE model that self-consistently adopt an IMF that respectively becomes bottom- or top-heavy in high-pressure environments for individual star-forming gas particles. In such models, the excess stellar mass-to-light ($M/L$) ratio with respect to a reference IMF is increased due to an overabundance of low-mass dwarf stars or stellar remnants, respectively. Crucially, both pressure-dependent IMFs have been calibrated to reproduce the observed trends of increasing excess $M/L$ with central stellar velocity dispersion ($σ_e$) in early-type galaxies, while maintaining agreement with the observables used to calibrate the EAGLE model, namely the galaxy luminosity function, half-light radii of late-type galaxies, and black hole masses. We find that while the $M/L$ excess is a good measure of the IMF for low-mass slope variations, it depends strongly on the age of the stellar population for high-mass slope variations. The normalization of the [Mg/Fe]$-σ_e$ relation is decreased (increased) for bottom- (top-)heavy IMF variations, while the slope is not strongly affected. Bottom-heavy variations have little impact on galaxy metallicities, half-light radii of early-type galaxies, or star formation rates, while top-heavy variations significantly increase these quantities for high-mass galaxies, leading to tension with observations.
Galaxy catalogs from the SAGE Semi-Analytic Model calibrated on THE THREE HUNDRED hydrodynamical simulations: A method to push the limits toward lower mass galaxies in dark matter only clusters simulations
本研究在 THE THREE HUNDRED 的多分辨率仅暗物质模拟上运行 SAGE 半解析模型，并用粒子群优化依据同分辨率全物理流体模拟校准其参数，以生成包含低质量星系恒星与光度性质的星系目录。
The Pristine HeII Emitter near GN-z11: Constraining the Mass Distribution of the First Stars
Università degli Studi di Firenze（佛罗伦萨大学）；INAF/Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切尔奇天文台）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）；Cavendish Laboratory, University of Cambridge（剑桥大学卡文迪许实验室）；Department of Physics and Astronomy, University College London（伦敦大学学院物理与天文系）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Scuola Normale Superiore（比萨高等师范学院）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理研究所）
利用数值N体/流体动力学模拟方法，研究了在高红移的PopII GRBs（GRBIs）观测中，从不同初始质量函数（IMF）、产额和寿命的恒星星族中探测和区分PopIII星富集特征的可能性。PopIII和PopII的恒星形成制度，同时采用头重脚轻和Salpeter-like IMF的原始PopIII恒星形成。我们发现，部分GRBIIs托管在介质中以前丰富的PopIII星（PopIII为主）是模型独立的。典型的丰度比，如[Si/O] vs [C/O]和[Fe/C] vs [Si/C]，可以帮助从大质量和中等质量的PopIII恒星中分离富集，而低质量的第一颗恒星则与常规的PopII世代退化。拥有PopIII主导的GRBII的星系的性质对第一颗恒星质量的特定假设并不十分敏感。
TNG SAM: Bridging Hydrodynamical Complexity and Semi-Analytic Efficiency to Model Galaxy Formation
Center for Computational Astrophysics, Flatiron Institute（平顿研究所计算天体物理中心）；Department of Physics & Astronomy, Oberlin College（欧柏林学院物理与天文系）；School of Physics and Astronomy, Tel Aviv University（特拉维夫大学物理与天文学院）；Columbia University, Department of Astronomy（哥伦比亚大学天文学系）；The City University of New York（纽约市立大学）；Max-Planck-Institut für extraterrestrische Physik (MPE)（马克斯·普朗克地外物理研究所）
COLIBRE: calibrating subgrid feedback in cosmological simulations that include a cold gas phase
Leiden University（莱顿大学）；University of Vienna（维也纳大学）；University of Nottingham（诺丁汉大学）；Ecole Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；Università degli Studi di Milano Bicocca（米兰比可卡大学）；University of Durham（杜伦大学）
The COLIBRE project: cosmological hydrodynamical simulations of galaxy formation and evolution
Leiden University（莱顿大学）；Lorentz Institute for Theoretical Physics, Leiden University（莱顿大学洛伦兹理论物理研究所）；University of Vienna（维也纳大学）；University of Portsmouth（朴茨茅斯大学）；Università degli Studi di Milano Bicocca（米兰比可卡大学）；University of Durham（杜伦大学）
The abundance and radial distribution of faint and ultra-faint dwarfs in galaxy clusters
University of California, Riverside（加州大学河滨分校）；University of Victoria（维多利亚大学）；Carnegie Mellon University（卡内基梅隆大学）；Université de Strasbourg（斯特拉斯堡大学）；NSF NOIRLab（美国国家光学-红外天文研究实验室）
Massive Galaxy Halos Contain Less Inner Dark Matter Than Predicted
Peking University（北京大学）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Tsung-Dao Lee Institute, and Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University（上海交大泛亚量子科学中心及粒子物理与宇宙学上海市重点实验室，上海交通大学）；Department of Astronomy, School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院天文学系）
Improved strong lensing modelling of galaxy clusters using the Fundamental Plane: detailed mapping of the baryonic and dark matter mass distribution of Abell S1063
Model-Independent Measurement of Baryon Gas Fractions through Galaxy-Galaxy Lensing and the Kinematic Sunyaev-Zel'dovich Effect
University of California, Berkeley（加州大学伯克利分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Berkeley Center for Cosmological Physics（伯克利宇宙物理学中心）；University of Cambridge（剑桥大学）；Kavli Institute for Cosmology Cambridge（卡弗里宇宙学剑桥研究所）；Stanford University（斯坦福大学）；SLAC National Accelerator Laboratory（SLAC国家加速器实验室）
CLASH-VLT: The variance in the velocity anisotropy profiles of galaxy clusters
INAF-Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；IFPU-Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；Dipartimento di Fisica, Università degli Studi di Milano（米兰大学物理系）；Dipartimento di Fisica G. Occhialini, Università degli Studi di Milano-Bicocca（米兰比可卡大学G.奥恰利尼物理系）；Department of Physics and Earth Sciences, University of Ferrara（费拉拉大学物理与地球科学系）；Dipartimento di Fisica E. R. Caianiello, Università Degli Studi di Salerno（萨莱诺大学E.R.凯亚涅洛物理系）；INAF – Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）
