First Weak-lensing Results from “See Change”: Quantifying Dark Matter in the Two z ≳ 1.5 High-redshift Galaxy Clusters SPT-CL J2040–4451 and IDCS J1426+3508
- Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seoul 03722 (Korea, Republic of)
- Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon 34055 (Korea, Republic of)
- Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)
- Department of Astronomy, University of Florida, Bryant Space Science Center, Gainesville, FL 32611 (United States)
- Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States)
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
We present a weak-lensing study of SPT-CL J2040–4451 and IDCS J1426+3508 at z = 1.48 and 1.75, respectively. The two clusters were observed in our “See Change” program, a Hubble Space Telescope survey of 12 massive high-redshift clusters aimed at high-z supernova measurements and weak-lensing estimation of accurate cluster masses. We detect weak but significant galaxy shape distortions using infrared images from the Wide Field Camera 3 (WFC3), which has not yet been used for weak-lensing studies. Both clusters appear to possess relaxed morphology in projected mass distribution, and their mass centroids agree nicely with those defined by both the galaxy luminosity and X-ray emission. Using a Navarro–Frenk–White profile, for which we assume that the mass is tightly correlated with the concentration parameter, we determine the masses of SPT-CL J2040–4451 and IDCS J1426 + 3508 to be M{sub 200}=8.6{sub −1.4}{sup +1.7}×10{sup 14} M{sub ⊙} and 2.2{sub −0.7}{sup +1.1}×10{sup 14} M{sub ⊙}, respectively. The weak-lensing mass of SPT-CL J2040–4451 shows that the cluster is clearly a rare object. Adopting the central value, the expected abundance of such a massive cluster at z≳1.48 is only ∼0.07 in the parent 2500 sq. deg. survey. However, it is yet premature to claim that the presence of this cluster creates a serious tension with the current ΛCDM paradigm unless that tension will remain in future studies after marginalizing over many sources of uncertainties such as the accuracy of the mass function and the mass–concentration relation at the high-mass end. The mass of IDCS J1426+3508 is in excellent agreement with our previous Advanced Camera for Surveys-based weak-lensing result, while the much higher source density from our WFC3 imaging data makes the current statistical uncertainty ∼40% smaller.
- OSTI ID:
- 22875738
- Journal Information:
- Astrophysical Journal, Vol. 847, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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