2018A&A...610A..85S


Query : 2018A&A...610A..85S

2018A&A...610A..85S - Astronomy and Astrophysics, volume 610A, 85-85 (2018/2-1)

Precise weak lensing constraints from deep high-resolution Ks images: VLT/HAWK-I analysis of the super-massive galaxy cluster RCS2 J 232727.7-020437 at z = 0.70.

SCHRABBACK T., SCHIRMER M., VAN DER BURG R.F.J., HOEKSTRA H., BUDDENDIEK A., APPLEGATE D., BRADAC M., EIFLER T., ERBEN T., GLADDERS M.D., HERNANDEZ-MARTIN B., HILDEBRANDT H., HOAG A., KLAES D., VON DER LINDEN A., MARCHESINI D., MUZZIN A., SHARON K. and STEFANON M.

Abstract (from CDS):

We demonstrate that deep good-seeing VLT/HAWK-I Ks images complemented with g+z-band photometry can yield a sensitivity for weak lensing studies of massive galaxy clusters at redshifts 0.7≤z≤1.1, which is almost identical to the sensitivity of HST/ACS mosaics of single-orbit depth. Key reasons for this good performance are the excellent image quality frequently achievable for Ks imaging from the ground, a highly effective photometric selection of background galaxies, and a galaxy ellipticity dispersion that is noticeably lower than for optically observed high-redshift galaxy samples. Incorporating results from the 3D-HST and UltraVISTA surveys we also obtained a more accurate calibration of the source redshift distribution than previously achieved for similar optical weak lensing data sets. Here we studied the extremely massive galaxy cluster RCS2 J232727.7-020437 (z=0.699), combining deep VLT/HAWK-I Ks images (point spread function with a 0.''35 full width at half maximum) with LBT/LBC photometry. The resulting weak lensing mass reconstruction suggests that the cluster consists of a single overdensity, which is detected with a peak significance of 10.1σ. We constrained the cluster mass to M200c/1015M)=2.06+0.28–0.26(stat.)±0.12(sys.) assuming a spherical Navarro, Frenk & White model and simulation-based priors on the concentration, making it one of the most massive galaxy clusters known in the z≥0.7 Universe. We also cross-checked the HAWK-I measurements through an analysis of overlapping HST/ACS images, yielding fully consistent estimates of the lensing signal.

Abstract Copyright: © ESO 2018

Journal keyword(s): gravitational lensing: weak - galaxies: clusters: individual: RCS2 J232727.7-020437

Simbad objects: 6

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Number of rows : 6
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 ACT-CL J0102-4915 ClG 01 02 52.50 -49 14 58.0           ~ 228 0
2 NAME Hubble Ultra Deep Field reg 03 32 39.0 -27 47 29           ~ 1661 0
3 ClG J0744+3927 ClG 07 44 52.5 +39 27 30           ~ 181 0
4 NAME COSMOS Field reg 10 00 28.60 +02 12 21.0           ~ 2963 0
5 ClG J1226+3332 ClG 12 26 57.7 +33 32 50           ~ 215 0
6 ACT-CL J2327.4-0204 ClG 23 27 27.60 -02 04 37.4           ~ 39 0

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