We present an analysis of weak lensing observations for RXJ1347–1145 over a 43 ^ { \prime } \times 43 ^ { \prime } field taken in B and R filters on the Blanco 4m telescope at CTIO .
RXJ1347–1145 is a massive cluster at redshift z = 0.45 .
Using a population of galaxies with 20 < R < 26 , we detect a weak lensing signal at the p < 0.0005 level , finding best-fit parameters of \sigma _ { v } = 1400 ^ { +130 } _ { -140 } km s ^ { -1 } for a singular isothermal sphere model and r _ { 200 } = 3.5 ^ { +0.8 } _ { -0.2 } Mpc with c = 15 ^ { +64 } _ { -10 } for a NFW model in an \Omega _ { m } = 0.3 , \Omega _ { \Lambda } = 0.7 cosmology .
In addition , a mass to light ratio M/ L _ { R } = 90 \pm 20 ~ { } M _ { \odot } / L _ { R \odot } was determined .
These values are consistent with the previous weak lensing study of RXJ1347–1145 by Fischer & Tyson ( 9 ) , giving strong evidence that systemic bias was not introduced by the relatively small field of view in that study .
Our best-fit parameter values are also consistent with recent X-ray studies by Allen et al .
( 1 ) and Ettori et al .
( 7 ) but are not consistent with recent optical velocity dispersion measurements by Cohen & Kneib ( 6 ) .