Dissecting the Strong-lensing Galaxy Cluster MS 0440.5+0204. II. New Optical Spectroscopic Observations in a Wider Area and Cluster Dynamical State

We present an optical study of the strong lensing galaxy cluster MS 0440.5$+$0204 at $z=0.19593$, based on CFHT/MegaCam g', r'-photometry and GMOS/Gemini CFHT/MOS/SIS spectroscopy in a broader area compared to previous works. have determined new spectroscopic redshifts for most prominent gravitational arcs surrounding central cluster. The information provided by photometric catalog yield us perform detailed weak mass reconstruction large number member galaxies covered our observations allow estimate more accurately velocity dispersion examine detail nature surroundings structures. dynamical is good agreement with inferred from analysis X-ray estimates. About $\sim$68\% are located inner $\lesssim$0.86 h$^{-1}_{70}$ Mpc region redshift distribution shows complex structure least three sub-structures along line-of-sight. Other also identified density map map. North-East overdensity distributed filament between ZwCL 0441.1$+$0211 clusters, suggesting that these two structures might be connected. 0440$+$0204 appears dynamically active, core likely experiencing merging process other nearby groups projected distances $\lesssim$1 could being accreted