来自KiDS的增长：基于千度巡天数据研究z=2以来星系的恒星质量增长

中文摘要 AI 辅助

我们利用来自KiDS DR4的2800万个星系测量了z=0-2的星系恒星质量函数，其有效巡天面积为676.9平方度。结合九波段测光（u至Ks波段）和基于深度学习测光得到的红移，我们使用了五种SED拟合配置，包括CIGALE/LePhare以及CB19/BC03/M05恒星种群合成（SPS）模型。我们展示了与代码、SPS建模和恒星形成历史（SFH）相关的系统效应的影响，这些因素综合起来可引入约0.6 dex的系统误差。本工作描绘的GSMF与以往研究（在系统误差引入的不确定性范围内）吻合良好，以往研究由于体积有限，通常只能覆盖log(M*/M_sun)约11.75以内的GSMF测量。KiDS的大面积和星系数量使我们能够对“极端”高质量端获得一些见解，我们的GSMF表明，在log(M*/M_sun)>11.75处，可能存在比简单指数截断所预期的更多的大质量星系。然而，我们提醒注意，尽管在红移估计技术和SPS方面取得了进展，但仍需未来研究来确认这一行为。我们通过两种不同方法考虑了爱丁顿偏差（EB）对我们观测的影响，并将我们的结果与半解析模型和流体动力学模拟的预测进行了比较。我们使用残差的平均绝对差（MAD）作为诊断指标。由于观测与爱丁顿偏差模拟之间发现的不一致性（>0.5 dex），特别是在高质量端，我们建议一些理论模型在参数调整时，如果事先考虑EB的影响，然后再调整与恒星物理和反馈相关的不确定参数，将会取得更好的性能。

英文摘要

We measure the galaxy stellar mass function at $z = 0-2$ using 28M galaxies from the KiDS DR4 which spans an effective survey area of 676.9 deg$^2$. Combining nine-band photometry ($u$--$K_s$) and redshifts derived using deep learning photometry, we use five SED fitting configurations, CIGALE/LePhare and CB19/BC03/M05 Stellar Population Synthesis (SPS). We present the impact of the systematics related to the code, SPS modeling and Star formation History (SFH) , which combined can introduce systematics of $\sim 0.6$ dex. The GSMFs outlined in this work agree well with previous studies (within the uncertainties introduced by systematics) that typically are able to cover measurements for the GSMF only up to $\log(M_*/M_\odot)\sim 11.75$, due to their limited volume. The large KiDS area and galaxy counts, allows us to gain some insights on the ``extreme" high-mass end, and our GSMFs imply that possibly there are more massive galaxies than we would expect, from a simple exponential cut-off, at $\log(M_*/M_\odot)>11.75$. However, we heed caution that despite advances done both in redshift estimation techniques and SPS, future studies are required to confirm this behavior. We consider the effects of Eddington-bias (EB) to our observations via two different methods and compare our results with the predictions of semi-analytic models and hydrodynamical simulations. We use the Mean Absolute Difference (MAD) of residuals as a diagnostic metric. Due to inconsistencies ($> 0.5$ dex) between observations and Eddington biased simulations found, especially at the high mass end, we suggest that some theoretical models would achieve better performance once parameter tuning takes into account the effects of EB prior to the tuning of the uncertain parameters involved related to stellar physics and feedback.

发表机构

• Sun Yat-sen University（中山大学）
• University Federico II（那不勒斯费德里科二世大学）
• INAF – Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）
• Zhengzhou University（郑州大学）
• Shanghai Jiao Tong University（上海交通大学）
• Tianjin Normal University（天津师范大学）

机构由 AI 辅助整理，请以论文原文为准。