Resolved spectroscopy of cluster galaxies at z~1.4

The star formation rate density of the universe peaks at z=1-3 and has subsequently declined to the present day. We our focusing our attention of the decline of star formation in the densest environments at z~1.5. I will present results that spatially resolve the gas properties of star-forming galaxies in the clusters XMMXCS2215 (z~1.47) and XMMUJ2235 (z~1.39), taken from the KMOS Cluster Survey (KCS). We have used this state-of-the-art IFU data to obtain the star formation rate and dynamical properties of the galaxies, and have combined this with morphology from HST imaging. From this we obtain median ratio of stellar mass to dynamical mass of 0.38. On average, for the galaxies in XMMXCX2215 54% of the total galaxy mass is stellar mass and for XMMUJ2235 this is much lower at approximately 35%. The majority of our sample is rotation dominated with a median v/sigma of 2.55, this being higher in the z~1.39 cluster. We find a rotation- to dispersion-dominated galaxy ratio of 5 across both clusters. Quantifying these parameters are crucial in determining the impact of environmental quenching mechanisms in z=1.4 clusters.