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arXiv 2408.02230astro-ph.GA
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模拟观测:TNG100模拟中的三类星系对齐

Mock Observations: Three Different Types of Galaxy Alignment in TNG100 Simulations

Yanyao Lan, Lin Tang, Weipeng Lin, Junyu Gong

AI总结:

本研究基于TNG100-1模拟开展模拟观测,探究三类星系内禀对齐的特征、影响因素及邻近效应,验证了模拟观测对公平比较模拟预测与实际观测的重要性。

摘要:

本研究基于TNG100-1模拟结果,采用模拟观测技术生成星系样本,旨在探究三类内禀对齐现象:最亮星系团星系(BGG)的取向与其卫星星系空间分布之间的卫星-中心对齐、卫星星系取向与指向其BGG方向之间的径向对齐,以及BGG取向与其卫星星系取向之间的直接对齐。总体而言,星系对齐的预测结果与观测基本一致,但也发现了一些微小差异。对于卫星-中心对齐,模拟观测很好地复现了对齐强度及颜色依赖趋势。就径向对齐而言,信号虽弱但可辨识,且无明显的颜色依赖性。至于直接对齐,未检测到信号,也不存在颜色依赖性。我们还研究了对齐对暗物质晕或BGG属性的依赖关系,以及邻近效应。对于卫星-中心对齐,预测的对齐信号与暗物质晕质量、BGG质量呈正相关,这与观测及先前的预测一致。在BGG年龄和金属丰度方面也观测到了类似的相关性,有待未来观测分析加以验证。三类对齐均观测到邻近效应:距离BGG越近的卫星星系,其对齐信号越强。本文还分析了星系定义和形状测定对对齐研究的影响。本研究强调了采用模拟观测技术对预测结果与观测结果进行公平比较的重要性。

英文摘要:

In this study, galaxy samples have been generated using mock observation techniques based on the results of TNG100-1 simulations to investigate three forms of intrinsic alignment: satellite-central alignment between the orientation of the brightest group galaxies (BGG) and the spatial distribution of their satellites, radial alignment between the satellites' orientation and the direction toward their BGG, as well as direct alignment between the orientation of BGG and that of its satellites. Overall, the predictions of galaxy alignment generally align with observations, although minor discrepancies have been identified. For satellite-central alignment, the alignment strength and color-dependence trends are well replicated by the mock observations. Regarding radial alignment, the signals are weak but discernible, with no apparent color dependence. As for direct alignment, no signal is detected, nor is there any color dependence. We also investigate the alignment dependencies on halo or the BGG properties, and proximity effect. For satellite-central alignment, the predicted alignment signal shows a positive correlation with halo and BGG mass, consistent with observations and previous predictions. Similar correlations have also been observed with the BGG age and metallicity, which merit future observational analysis for confirmation. Proximity effects have been observed for all three types of alignment, with satellites closer to the BGG exhibiting stronger alignment signals. The influence of galaxy definition and shape determination on alignment studies is also analyzed. This study underscores the importance of employing mock observation techniques for a fair comparison between predictions and observations.

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。

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