Mass Calibration of the CODEX Cluster Sample using SPIDERS Spectroscopy -- I. The Richness-Mass Relation

Understand

We use galaxy dynamical information to calibrate the richness-mass scaling relation of a sample of 428 galaxy clusters that are members of the CODEX sample with redshifts up to z~0.7.

• These clusters were X-ray selected using the ROSAT All-Sky Survey (RASS), cross-matched to associated systems in the redMaPPer catalog from the Sloan Digital Sky Survey.
• The spectroscopic sample we analyze was obtained in the SPIDERS program and contains ~7800 red member galaxies.
• Adopting NFW mass and galaxy density profiles and a broad range of orbital anisotropy profiles, we use the Jeans equation to calculate halo masses.