arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2307.03218astro-ph.GA
收藏

宇宙学背景下星系并合对卫星星系平面的印记

The imprint of galaxy mergers on satellite planes in a cosmological context

Kosuke Jamie Kanehisa, Marcel S. Pawlowski, Oliver Müller

AI总结:

基于IllustrisTNG模拟,本文首次在宇宙学背景下统计检验星系主并合对卫星星系平面的影响,发现并合无法有效形成观测到的扁平相干卫星平面,仅能略微增强相空间相关性。

摘要:

在本星系群邻近的Local Volume中,已观测到扁平的、运动学上相互关联的矮卫星星系平面结构。宿主星系并合过程中卫星星系被甩出,曾被提出是这类特殊结构的形成机制之一。我们利用IllustrisTNG流体力学模拟套件,首次在完整宇宙学背景下统计检验了主并合对当前时刻卫星星系系统的影响。质量比大于1/3的并合通常对观测上受关注的卫星星系在相空间中的相关性影响可以忽略,甚至产生不利影响。即使是高角动量的并合,由于模拟中卫星星系分布具有延展性质,也难以有效地将卫星星系向外甩出。此外,任何潜在的并合印记都会部分被并合后新吸积的卫星星系所冲淡,而自并合开始时就束缚于并合暗晕中的卫星星系会受到潮汐瓦解和质量剥离,从而在2–5 Gyr后使并合对当前时刻最大质量卫星星系分布的影响降至最低。当我们将样本限制为在其系统最后一次并合整个期间始终束缚于宿主暗晕的卫星星系时,并未发现其相空间相关性有特别改善。相反,这类参与并合的卫星星系在并合期间及之后其径向分布发生收缩,导致绝对平面高度更小(但轴比相当)。总体而言,在统计样本中,主并合似乎并不能形成相互关联的平面结构。能够有效将其角动量传递给卫星星系分布的并合,可以略微增强卫星星系的相空间相关性,但无法形成我们在本地宇宙中观测到的那种高度扁平且轨道上相干的位形。

英文摘要:

Flattened and kinematically correlated planes of dwarf satellite galaxies have been observed in the Local Volume. The slinging out of satellites during host galaxy mergers has been suggested as a formation mechanism for these peculiar structures. We statistically examined the impact of major mergers on present-time satellite systems for the first time in a full cosmological context using the IllustrisTNG suite of hydrodynamic simulations. Mergers with mass ratios above 1/3 generally have a negligible or adverse impact on the phase-space correlation of observationally motivated satellites. Even high-angular momentum mergers are inefficient at slinging satellites outward due to the extended nature of simulated satellite distributions. Furthermore, any potential merger imprint is partially washed out by post-merger accretion of satellites, while satellites bound to the merging haloes since the merger's beginning are disrupted and stripped of mass - minimising the merger's influence on the present-time distribution of the most massive satellites after 2-5 Gyr. Constraining our sample to satellites bound to their host throughout the full duration of their system's last merger, we recover no particular improvement in their phase-space correlation. Instead, such participant satellites experience a contraction of their radial distribution during and after the merger, resulting in smaller absolute plane heights (but comparable axis ratios). Overall, major mergers do not appear to form correlated planes in a statistical sample. Mergers that efficiently transfer their angular momentum to satellite distributions can marginally enhance their phase-space correlation, but cannot form highly flattened and orbitally coherent configurations as observed in our local Universe.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑