CLASH: 对Abell 2261质量分布的精确新约束
宇宙学与河外天体物理
2015-06-03 v1
摘要
我们首次精确约束了Abell 2261 (z=0.225)的内部质量分布，并确定该星系团并非先前发现的“过度集中”，这意味着其形成时间与{\Lambda}CDM预期一致。这些结果基于作为哈勃望远镜星系团透镜和超新星巡天(CLASH)一部分的新16波段HST成像的强透镜分析。结合对斯巴鲁宽场成像(含5波段斯巴鲁+KPNO测光)的修正弱透镜分析，我们在假设球对称晕的情况下，对晕的维里质量M_vir = 2.2±0.2×10^15 M⊙/h70 (在r ≈ 3 Mpc/h70内)和浓度c = 6.2 ± 0.3施加了严格的新约束。这与近期{\Lambda}CDM模拟的平均c(M,z)预测大致一致，其范围在5 <~ <c> <~ 8之间。我们最重要的系统不确定性是沿视线方向的晕伸长。为了估计这一点，我们还基于存档的钱德拉X射线观测推导了质量分布，发现在r2500 ~ 600 kpc处，其比我们的透镜推导分布低约35%。通过一个沿视线方向轴比约为2:1的伸长晕模型可以实现一致性。对于这个伸长晕模型，我们得到M_vir = 1.7±0.2×10^15 M⊙/h70和c_vir = 4.6±0.2，给出了这些值的粗略下限。对晕伸长的需求可以部分由非热压力支持来弥补，或许完全由X射线质量测量的系统误差来弥补。我们基于MMT/Hectospec光谱红移估计了背景结构的影响，发现这些影响倾向于进一步降低Mvir约7%，并增加cvir约5%。
引用
@article{arxiv.1201.1616,
title = {CLASH: Precise New Constraints on the Mass Profile of Abell 2261},
author = {Dan Coe and Keiichi Umetsu and Adi Zitrin and Megan Donahue and Elinor Medezinski and Marc Postman and Mauricio Carrasco and Timo Anguita and Margaret J. Geller and Kenneth J. Rines and Antonaldo Diaferio and Michael J. Kurtz and Larry Bradley and Anton Koekemoer and Wei Zheng and Mario Nonino and Alberto Molino and Andisheh Mahdavi and Doron Lemze and Leopoldo Infante and Sara Ogaz and Peter Melchior and Ole Host and Holland Ford and Claudio Grillo and Piero Rosati and Yolanda Jiménez-Teja and John Moustakas and Tom Broadhurst and Begoña Ascaso and Ofer Lahav and Matthias Bartelmann and Narciso Benítez and Rychard Bouwens and Or Graur and Genevieve Graves and Saurabh Jha and Stephanie Jouvel and Daniel Kelson and Leonidas Moustakas and Dan Maoz and Massimo Meneghetti and Julian Merten and Adam Riess and Steve Rodney and Stella Seitz},
journal= {arXiv preprint arXiv:1201.1616},
year = {2015}
}
备注
Submitted to the Astrophysical Journal. 19 pages, 14 figures