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ID 47044
本文ファイル
著者
Futamase, Toshifumi
Kijisawa, Masaru
Kuroshima, Risa
キーワード
galaxies: clusters: individual (Coma Cluster (A1656)) – gravitational lensing: weak – X-rays: galaxies: clusters
NDC
天文学・宇宙科学
抄録(英)
We present a 4 deg^2 weak gravitational lensing survey of subhalos in the very nearby Coma cluster using the Subaru/Suprime-Cam. The large apparent size of cluster subhalos allows us to measure the mass of 32 subhalos detected in a model-independent manner, down to the order of 10^−3 of the virial mass of the cluster. Weak-lensing mass measurements of these shear-selected subhalos enable us to investigate subhalo properties and the correlation between subhalo masses and galaxy luminosities for the first time. The mean distortion profiles stacked over subhalos show a sharply truncated feature which is well-fitted by a Navarro–Frenk–White (NFW) mass model with the truncation radius, as expected due to tidal destruction by the main cluster. We also found that subhalo masses, truncation radii, and mass-to-light ratios decrease toward the cluster center. The subhalo mass function, dn/d ln M_sub, in the range of 2 orders of magnitude in mass, is well described by a single power law or a Schechter function. Best-fit power indices of 1.09^+0.42_−0.32 for the former model and 0.99^+0.34_−0.23 for the latter, are in remarkable agreement with slopes of ∼0.9–1.0 predicted by the cold dark matter paradigm. The tangential distortion signals in the radial range of 0.02–2 h^−1 Mpc from the cluster center show a complex structure which is well described by a composition of three mass components of subhalos, the NFW mass distribution as a smooth component of the main cluster, and a lensing model from a large scale structure behind the cluster. Although the lensing signals are 1 order of magnitude lower than those for clusters at z ∼ 0.2, the total signal-to-noise ratio, S/N = 13.3, is comparable, or higher, because the enormous number of background source galaxies compensates for the low lensing efficiency of the nearby cluster.
内容記述
This work was supported by World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan.
掲載誌名
The Astrophysical Journal
784巻
2号
開始ページ
90
出版年月日
2014-04-01
出版者
IOP Publishing
ISSN
0004-637X
1538-4357
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
publisher
権利情報
© 2014. The American Astronomical Society. All rights reserved.
関連情報URL
部局名
理学研究科