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تسجيل مستخدم جديدAssembling a RELIC at Redshift 1: Spectroscopic Observations of Galaxies in the RELICS Cluster SPT-CLJ0615-5746
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We present a catalog of spectroscopic redshifts for SPT-CLJ0615$-$5746, the most distant cluster in the Reionization Lensing Cluster Survey (RELICS). Using Nod & Shuffle multi-slit observations with LDSS-3 on Magellan, we identify ${sim}50$ cluster members and derive a cluster redshift of $z_c = 0.972$, with a velocity dispersion of $sigma = 1235 pm 170 textrm{km} textrm{s}^{-1}$. We calculate a cluster mass using a $sigma_{200}-M_{200}$ scaling relation of $M_{200} = (9.4 pm 3.6) times 10^{14} M_odot$, 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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