TY - JOUR
T1 - Hubble space telescope weak-lensing study of the galaxy cluster xmmu j2235.3 - 2557 at z 1.4
T2 - A surprisingly massive galaxy cluster when the universe is one-third of its current age
AU - Jee, M. J.
AU - Rosati, P.
AU - Ford, H. C.
AU - Dawson, K. S.
AU - Lidman, C.
AU - Perlmutter, S.
AU - Demarco, R.
AU - Strazzullo, V.
AU - Mullis, C.
AU - Böhringer, H.
AU - Fassbender, R.
PY - 2009
Y1 - 2009
N2 - We present a weak-lensing analysis of the z ≃ 1.4 galaxy cluster XMMU J2235.3 - 2557, based on deep Advanced Camera for Surveys images. Despite the observational challenge set by the high redshift of the lens, we detect a substantial lensing signal at the ≳8σ level. This clear detection is enabled in part by the high mass of the cluster, which is verified by our both parametric and non-parametric estimation of the cluster mass. Assuming that the cluster follows a Navarro-Frenk-White mass profile, we estimate that the projected mass of the cluster within r = 1 Mpc is (8.5 1.7) × 10 14 M, where the error bar includes the statistical uncertainty of the shear profile, the effect of possible interloping background structures, the scatter in concentration parameter, and the error in our estimation of the mean redshift of the background galaxies. The high X-ray temperature 8.6 +1.3 -1.2 keV of the cluster recently measured with Chandra is consistent with this high lensing mass. When we adopt the 1σ lower limit as a mass threshold and use the cosmological parameters favored by the Wilkinson Microwave Anisotropy Probe 5-year (WMAP5) result, the expected number of similarly massive clusters at z ≳ 1.4 in the 11 square degree survey is N 5 × 10-3. Therefore, the discovery of the cluster within the survey volume is a rare event with a probability ≲1% and may open new scenarios in our current understanding of cluster formation within the standard cosmological model.
AB - We present a weak-lensing analysis of the z ≃ 1.4 galaxy cluster XMMU J2235.3 - 2557, based on deep Advanced Camera for Surveys images. Despite the observational challenge set by the high redshift of the lens, we detect a substantial lensing signal at the ≳8σ level. This clear detection is enabled in part by the high mass of the cluster, which is verified by our both parametric and non-parametric estimation of the cluster mass. Assuming that the cluster follows a Navarro-Frenk-White mass profile, we estimate that the projected mass of the cluster within r = 1 Mpc is (8.5 1.7) × 10 14 M, where the error bar includes the statistical uncertainty of the shear profile, the effect of possible interloping background structures, the scatter in concentration parameter, and the error in our estimation of the mean redshift of the background galaxies. The high X-ray temperature 8.6 +1.3 -1.2 keV of the cluster recently measured with Chandra is consistent with this high lensing mass. When we adopt the 1σ lower limit as a mass threshold and use the cosmological parameters favored by the Wilkinson Microwave Anisotropy Probe 5-year (WMAP5) result, the expected number of similarly massive clusters at z ≳ 1.4 in the 11 square degree survey is N 5 × 10-3. Therefore, the discovery of the cluster within the survey volume is a rare event with a probability ≲1% and may open new scenarios in our current understanding of cluster formation within the standard cosmological model.
KW - Cosmology: observations
KW - Dark matter
KW - Galaxies: clusters: individual (XMMU J2235.3-2557)
KW - Galaxies: high-redshift
KW - Gravitational lensing
KW - X-rays: galaxies: clusters
UR - http://www.scopus.com/inward/record.url?scp=70549110126&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/704/1/672
DO - 10.1088/0004-637X/704/1/672
M3 - Article
AN - SCOPUS:70549110126
SN - 0004-637X
VL - 704
SP - 672
EP - 686
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
ER -