Department of Physics

# Staff profile

## Publication details for Prof Richard Massey

Mo W., Gonzalez A., Jee M.J., Massey R., Rhodes J., Brodwin M., Eisenhardt P., Marrone D.P., Stanford S.A. & Zeimann G.R. (2016). IDCS J1426.5+3508: Weak Lensing Analysis of a Massive Galaxy Cluster at z = 1.75. Astrophysical Journal 818(2): L25.

### Abstract

We present a weak lensing study of the galaxy cluster IDCS J1426.5+3508 at z = 1.75, which is the highest-redshift strong lensing cluster known and the most distant cluster for which a weak lensing analysis has been undertaken. Using F160W, F814W, and F606W observations with the Hubble Space Telescope, we detect tangential shear at 2σ significance. Fitting a Navarro–Frenk–White mass profile to the shear with a theoretical median mass-concentration relation, we derive a mass ${M}{200,\mathrm{crit}}={2.3}{-1.4}^{+2.1}\times {10}^{14}\;$ M⊙. This mass is consistent with previous mass estimates from the Sunyaev–Zel'dovich (SZ) effect, X-ray, and strong lensing. The cluster lies on the local SZ–weak lensing mass scaling relation observed at low redshift, indicative of minimal evolution in this relation.