论文标题
揭示星系与自校准和贴花DR3数据的内在对齐
Unveiling the Intrinsic Alignment of Galaxies with Self-Calibration and DECaLS DR3 data
论文作者
论文摘要
星系内在比对（IA）既是对宇宙剪切测量及其宇宙学应用的系统污染的来源，也是有关宇宙大规模结构和星系形成的有价值信息的来源。自校准（SC）方法\ citep {sc2008}旨在将IA与宇宙剪切分离，而没有IA建模。它首先成功地应用于KIDS450和KV450 DATA \ CITEP {YAO2019}。我们将SC方法应用于贴花DR3剪切 + Z-Z目录，并将IA检测显着提高到$ \ sim14σ$。我们发现IA对星系颜色的强烈依赖性，红色星系具有强IA信号（$ \sim1.6σ$），而蓝色星系的IA信号与零一致。红色星系的检测到的IA与非线性潮汐比对模型是合理吻合的，并且推断的IA振幅随着红移而增加。我们仔细地解决了SC方法中的系统，并进行了几次理智检查。我们讨论了各种警告，并可能在未来工作中解决的测量，理论和参数拟合方面进行改进。
Galaxy intrinsic alignment (IA) is both a source of systematic contamination to cosmic shear measurement and its cosmological applications, and a source of valuable information on the large scale structure of the universe and galaxy formation. The self-calibration (SC) method \citep{SC2008} was designed to separate IA from cosmic shear, free of IA modeling. It was first successfully applied to the KiDS450 and KV450 data \citep{Yao2019}. We apply the SC method to the DECaLS DR3 shear + photo-z catalog and significantly improve the IA detection to $\sim 14σ$. We find a strong dependence of IA on galaxy color, with strong IA signal ($\sim17.6σ$) for red galaxies, while the IA signal for blue galaxies is consistent with zero. The detected IA for red galaxies are in reasonable agreement with the non-linear tidal alignment model and the inferred IA amplitude increases with redshift. We address the systematics in the SC method carefully and performed several sanity checks. We discuss various caveats and possible improvements in the measurement, theory and parameter fitting that will be addressed in future works.
