基于自组织映射的表型红移：一种刻画弱引力透镜源星系红移分布的新方法
宇宙学与河外天体物理
2019-08-14 v2 星系天体物理
摘要
诸如暗能量巡天（DES）之类的宽场成像巡天依赖于在少数滤光片中对光谱能量分布的粗略测量来估计源星系的红移分布。在此情形下，样本方差、散粒噪声和选择效应限制了红移定标以及由此带来的宇宙学约束可达到的精度。我们提出了一种新方法，将宽场、少滤光片测量与来自深场的星表相结合，后者具有额外滤光片且测光噪声足够低以打破测光红移中的简并。多波段深场被用作宽场观测与精确红移之间的中介，大大减少了样本方差、散粒噪声和选择效应。我们对该方法的实现使用自组织映射根据观测流量将星系分组为表型，并使用由N体模拟创建的模拟DES星表进行了测试。在DES第三年弱引力透镜层析分析的理想化模拟中，它在五个层析红移区间的每个区间上给出了典型的平均红移不确定度，相比第一年分析改善了60%。尽管该方法的实现是针对DES定制的，其形式体系可应用于具有类似观测策略的其他大型测光巡天。
引用
@article{arxiv.1901.05005,
title = {Phenotypic redshifts with self-organizing maps: A novel method to characterize redshift distributions of source galaxies for weak lensing},
author = {R. Buchs and C. Davis and D. Gruen and J. DeRose and A. Alarcon and G. M. Bernstein and C. Sánchez and J. Myles and A. Roodman and S. Allen and A. Amon and A. Choi and D. C. Masters and R. Miquel and M. A. Troxel and R. H. Wechsler and T. M. C. Abbott and J. Annis and S. Avila and K. Bechtol and S. L. Bridle and D. Brooks and E. Buckley-Geer and D. L. Burke and A. Carnero Rosell and M. Carrasco Kind and J. Carretero and F. J. Castander and R. Cawthon and C. B. D'Andrea and L. N. da Costa and J. De Vicente and S. Desai and H. T. Diehl and P. Doel and A. Drlica-Wagner and T. F. Eifler and A. E. Evrard and B. Flaugher and P. Fosalba and J. Frieman and J. García-Bellido and E. Gaztanaga and R. A. Gruend and J. Gschwend and G. Gutierrez and W. G. Hartley and D. L. Hollowood and K. Honscheid and D. J. James and K. Kuehn and N. Kuropatkin and M. Lima and H. Lin and M. A. G. Maia and M. March and J. L. Marshall and P. Melchior and F. Menanteau and R. L. C. Ogando and A. A. Plazas and E. S. Rykoff and E. Sanchez and V. Scarpine and S. Serrano and I. Sevilla-Noarbe and M. Smith and M. Soares-Santos and F. Sobreira and E. Suchyta and M. E. C. Swanson and G. Tarle and D. Thomas and V. Vikram},
journal= {arXiv preprint arXiv:1901.05005},
year = {2019}
}
备注
24 pages, 11 figures; matches version accepted to MNRAS