Exploring the Impacts of Gas Accretion and Environment via Multivariate (Spatial) Analysis of Metals, Star formation, and Morphology of Nearby Subaru HSC Galaxies

我们的研究成果将在2023年发表在多篇论文中。我们研究可观测星系属性之间的多维关联，以检验我们对气体吸积和环境效应的理解。在SDSS HSC调查中，我测量了大约40,000个恒星形成星系(SFG)的不对称性和其他参数。这些测量结果和不对称性与金属丰度和恒星形成率(SFR)的趋势将发表在Yesuf等人的文章中。2023A。我们还测量了Illustrious TNG50中模拟星系的不对称性。我们证实，TNG50广泛复制了观察中看到的SFR的不对称趋势(Bottrell等人。2023年)。我们还发现宽线活动星系核(AGN)具有与SFG相似的不对称性和浓度(Yesuf等人。2023b；唐等人。为了计算不对称性和其他参数，我修改了统计变形代码。这些修改包括更好的图像分割和混合，使用光度红移来掩盖污染物，以及包裹体测量误差。我还计算了SDSS和GAMA调查的环境指标，这些测量用于研究HSC星系。我们和博士生Kiyoaki Omari一起，在模拟和HSC观测中研究了星系合并和环境之间的关系。我们发现，合并优先发现在低密度环境中(Omari等人。2023年)。我们和另一名学生徐海一起研究活动星系核的环境。我们的结果表明，活动星系核与SFG生活在相似的环境中(Xu等人)。2013；Yesuf 2023c)我已经在几所大学展示了我们的结果。

Our results will be published in several papers in 2023. We study the multi-dimensional association among observable galaxy properties to test our understanding of gas accretion and environmental effects. I measured asymmetry and other parameters for ~40,000 star-forming galaxies (SFGs) in SDSS+HSC surveys. These measurements and the trends of asymmetry with metallicity and star formation rate (SFR) will be presented in Yesuf et al. 2023a. We also measured asymmetry for simulated galaxies in Illustrious TNG50. We confirmed that TNG50 broadly reproduces trends of asymmetry with SFR seen in observations (Bottrell et al. 2023). We also find that broad-line active galactic nuclei (AGNs) have similar asymmetry and concentration as SFGs (Yesuf et al. 2023b; Tang et al. 2023).To compute asymmetry and other parameters, I modified the statmorph code. The modifications include better image segmentation and deblending, use of photometric redshifts to mask contaminants, and inclusion measurement errors. I also computed environmental indicators for SDSS and GAMA surveys and these measurements are used to study HSC galaxies.With a PhD student, Kiyoaki Omari, we investigated the relationship between galaxy mergers and environments in both simulations and HSC observations. We found that mergers are preferentially found in low-density environments (Omari et al. 2023). With another student, Hai Xu, we study environments of AGNs. Our results indicate that AGNs live in similar environments as SFGs (Xu et al. 2013; Yesuf 2023c).I have presented our results in several universities.