Description
We present a catalog of spectroscopic redshifts for SPT-CLJ0615-5746, the most distant cluster in the Reionization Lensing Cluster Survey. Using Nod & Shuffle multislit observations with LDSS-3 on Magellan, we identify ~50 cluster members and derive a cluster redshift of z_c_=0.972, with a velocity dispersion of {sigma}=1244+/-162km/s. We calculate a cluster mass using a {sigma}_200_-M_200_ scaling relation of M_200_=(9.6+/-3.5)x10^14^M_{sun}_, in agreement with previous, independent mass measurements of this cluster. In addition, we examine the kinematic state of SPT-CLJ0615-5746, taking into consideration prior investigations of this system. With an elongated profile in lensing mass and X-ray emission, a non-Gaussian velocity dispersion that increases with clustercentric radius, and a brightest cluster galaxy not at rest with the bulk of the system, there are multiple cluster properties that, while not individually compelling, combine to paint a picture that SPT-CLJ0615-5746 is currently being assembled.
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