We present a model to track the orbital evolution of "unresolved subhaloes" (USHs) in cosmological simulations. USHs are subhaloes that are no longer distinguished by halo finders as self-bound overdensities within their larger host system due to limited mass resolution. These subhaloes would host "orphan galaxies" in semi-analytic models of galaxy formation and evolution (SAMs). Predicting the evolution of the phase-space components of USHs is crucial for the adequate modelling of environmental processes, interactions and mergers implemented in SAMs that affect the baryonic properties of orphan satellites. Our model takes into account dynamical friction drag, mass loss by tidal stripping and merger with the host halo, involving three free parameters. To calibrate this model, we consider two DM-only simulations of different mass resolution (MultiDark simulations). The simulation with higher-mass resolution ({\sc smdpl}; $ m_{\rm DM} = 9.6 \times 10^7 ~ h^{-1}\,\mathrm{M_{\odot}}$) provides information about subhaloes that are not resolved in the lower-mass resolution one ({\sc mdpl2}; $ m_{\rm DM} = 1.5 \times 10^9 ~ h^{-1}\,\mathrm{M_{\odot}}$); the orbit of those USHs is tracked by our model. We use as constraining functions the subhalo mass function (SHMF) and the two-point correlation function (2PCF) obtained from {\sc smdpl}, being the latter a novel aspect of our approach. While the SHMF fails to put tight constraints on the efficiency of dynamical friction and the merger condition, the addition of clustering information helps to specify the parameters of the model related to the spatial distribution of subhaloes. Our model allows to achieve good convergence between the results of simulations of different mass resolution, with a precision better than 10 per cent for both SHMF and 2PCF.
Bloodhound Unleashed: Particle-based Substructure Tracking for Cosmological Simulations
The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Rensselaer Polytechnic Institute（伦斯勒理工学院）；University of California, Irvine（加州大学尔湾分校）；University of Southern California（南加州大学）
Mapping the Information Geometry of an Unresolved Dark Matter Population using a Differentiable Strong Lensing Simulator
Université de Montréal（蒙特利尔大学）；Mila - Quebec Artificial Intelligence Institute（魁北克人工智能研究所米拉）；Ciela - Montreal Institute for Astrophysical Data Analysis and Machine Learning（蒙特利尔天体物理数据分析与机器学习研究所）
Solving Milky Way-sized Systems with Haskap Pie: A Halo finding Algorithm with efficient Sampling, K-means clustering, tree-Assembly, Particle tracking, Python modules, Inter-code applicability, and Energy solving
Symfind: Addressing the Fragility of Subhalo Finders and Revealing the Durability of Subhalos
SLAC National Accelerator Laboratory（SLAC国家加速器实验室）；Department of Physics, Stanford University（斯坦福大学物理系）；Carnegie Observatories（卡内基观测站）；Department of Astronomy, University of Maryland, College Park（马里兰大学帕克分校天文学系）
The evolution of the baryonic content and mass profiles of satellite galaxies in the MTNG simulations
Universidad de Sevilla（塞维利亚大学）；Donostia International Physics Center（圣塞巴斯蒂安国际物理中心）；IKERBASQUE, Basque Foundation for Science（伊克尔巴斯克，巴斯克科学基金会）；INFN – Istituto Nazionale di Fisica Nucleare, Sezione di Bologna（意大利国家核物理研究所博洛尼部分所）；University of Cambridge（剑桥大学）；Kavli Institute for Cosmology Cambridge（剑桥卡弗里宇宙学研究所）；Durham University（杜伦大学）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森天体物理中心）；Max Planck Institute for Astrophysics（马克斯·普朗克天体物理研究所）
