AI 中文总结
本研究基于Magneticum模拟分析星系团矮星系的投影相空间，构建下落时间模板，发现30%以上近期并合星系位于古老并合星系主导区域，还揭示矮星系三维径向分布更宽及暗物质缺失星系轨道变化的规律。
AI 中文摘要
当前研究致力于观测星系团中矮星系的光谱样本，以分析它们在投影相空间（PPS，即视线速度与投影团心距的关系）中的分布及相关趋势。我们利用Magneticum套件宇宙学模拟中星系团内已分辨的重子晕，补充了此前研究中对矮星系群体（恒星质量$M_\text{\tiny*}<10^9M_\text{\tiny\bigodot}$）的专门关注，以及对下落时间与PPS位置之间相关性的分析。推断出的趋势重现了此前研究报道的径向相关性，但我们发现相当大比例（≥30%）的近期并合星系位于此前预测为古老并合星系主导的区域。以3 Gyr的下落时间阈值划分该图，我们在PPS中构建了详细的下落时间模板。我们提供这些数据，以便观测者将样本置于PPS时能统计推断其并合时间。此外，我们回顾了不同轨道在PPS中的轨迹及其对观测者取向的依赖性。与大质量星系相比，我们发现矮星系在三维相空间（PS）中的径向分布宽得多。利用一组高分辨率理想化模拟，我们预测缺乏暗物质的星系轨道会发生显著改变。
英文摘要
Ongoing effort is devoted to observing spectroscopic samples of dwarf galaxies in clusters, allowing the analysis of their distribution and associated trends in projected phase-space (PPS), i.e. line-of-sight velocity vs. projected clustercentric distance. By utilizing the resolved baryonic halos inside the galaxy clusters of a cosmological simulation from the Magneticum suite, we complement on prior studies with dedicated focus on the dwarf galaxy population ($M_\ast<10^9\,M_\odot$) and correlations between infall time and location in PPS. The inferred trend recovers the radial correlation reported by prior works, but we find a significant fraction ($\geq30\%$) of recently accreted galaxies at locations that were previously predicted to be dominated by ancient infallers. Splitting the diagram with an infall time threshold of 3 Gyr, we develop a detailed infall time template in PPS. We provide our data to allow observers to statistically infer the time of infall of their sample when placing them on the PPS. Additionally, we review the trajectories in PPS of different orbits and their dependence on the observer's orientation. Compared to massive galaxies, we find a much broader radial distribution for dwarfs in 3D PS. Utilizing a set of high-resolution idealized simulations, we predict strongly altered orbits for dark matter-deficient galaxies.
Comments17 pages, 11 figures. Submitted to ApJ, comments are welcome
