发表机构
Yonsei University（延世大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出基于模型框架定义BCG与ICL的孔径分离，利用半解析模型确定孔径半径，在不同红移下进行测试，结果显示质量趋势相似，恢复的BCG和ICL质量较准确，为观测与模型联系提供了基于物理的孔径定义。
AI 中文摘要
我们提出了一个基于模型的框架，用于定义最亮星系团星系（BCG）和星系团内光（ICL）之间的孔径分离。利用半解析模型\texttt{FEGA25}预测的固有BCG和ICL成分，我们为每个晕确定使恢复的ICL质量偏差最小的孔径半径。通过平衡孔径外的BCG恒星质量和孔径内的ICL质量来获得最佳半径。在\(z = 0\)时，以物理单位表示的最佳孔径随晕质量增加，近似为\(r_{\rm cut}\propto M_{\rm halo}^{0.28}\)，接近预期的维里标度。以维里半径为单位时，孔径几乎与晕质量无关，在\(10^{14}M_\odot\)时\(r_{\rm cut}/R_{\rm vir}\simeq 0.045\)。应用所得孔径规定，我们恢复的固有BCG质量优于8%（最低百分位数），而ICL质量恢复的中值非常接近1，平均散射为\(\pm 3\%\)。将分析扩展到\(z = 1\)和\(z = 2\)，我们发现质量趋势相似，\(r_{\rm cut}/R_{\rm vir}\)的斜率和截距保持稳定。稳健性测试表明，推断的孔径对ICL浓度和BCG大小最敏感，但主要趋势得以保留。我们的结果为将观测到的BCG-ICL测量与固有模型成分联系起来提供了一个基于物理的孔径定义。
英文摘要
We present a model-based framework to define an aperture separation between the brightest cluster galaxy (BCG) and the intracluster light (ICL). Using the intrinsic BCG and ICL components predicted by the semi-analytic model \texttt{FEGA25}, we determine, for each halo, the aperture radius that minimizes the bias in the recovered ICL mass. The optimal radius is obtained by balancing the BCG stellar mass lying outside the aperture with the ICL mass enclosed within it. At $z=0$, the optimal aperture in physical units increases with halo mass approximately as $r_{\rm cut}\propto M_{\rm halo}^{0.28}$, close to the expected virial scaling. When expressed in units of the virial radius, the aperture becomes nearly independent of halo mass, with $r_{\rm cut}/R_{\rm vir}\simeq 0.045$ at $10^{14}M_\odot$. Applying the resulting aperture prescriptions, we recover the intrinsic BCG mass to better than 8\% (lowest percentile), while the ICL mass is recovered with median values very close to unity, and an average scatter of $\pm 3\%$. Extending the analysis to $z=1$ and $z=2$, we find that the mass trends remain similar, with the slope and intercept of $r_{\rm cut}/R_{\rm vir}$ that stay stable. Robustness tests show that the inferred aperture is most sensitive to the ICL concentration and BCG size, but the main trends are preserved. Our results provide a physically motivated aperture definition for connecting observational BCG--ICL measurements to intrinsic model components.
Comments15 pages, 8+1 figures, accepted for publications in ApJS after minor revision
