X-RAY-OPTICAL SCALING RELATIONS FOR THE DARK ENERGY SURVEY Y3 REDMAPPER CLUSTERS

Physical and Biological Sciences

Astrophysics

Studies of galaxy clusters have proven successful cosmological probes. They are known to be the largest structures to have become gravitationally stable and enter into a state of virial equilibrium allowing us to infer valuable information about dark energy. Thus we are interested in analyzing clusters identified in the Dark Energy Survey Y3 (DES Y3) and work toward placing strong constraints on the dark energy equation of state parameter, ω_λ by analyzing the number density of galaxy clusters across a range of redshifts as a function of cluster mass. Given the fact that direct measurement of cluster mass is not yet possible, here in this work we look at the correlation of richness for clusters in DES Y3 with X-ray temperatures and X-ray luminosities which relate to cluster mass, where richness is the number of galaxies within a cluster. We introduce the Cluster Scaling Relation (CluStR) fitting algorithm responsible for calculating scaling relations between observables by incorporating the Bayesian approach developed by Brandon Kelly. Finally, we then present our results as the following; an r2500 TX-λ scaling relation of ln(E(z)^(-2/3) kBTX,r2500) = (0.38 ± 0.06) ln( λ/98 ) + 1.92 ± 0.02 results for 167 ’detected’ clusters with an intrinsic scatter σ_intr = 0.28 ± 0.02 and an r2500 LX-λ scaling relation of ln( L_X,r2500/E(z)^(10E44)) = (1.19 ± 0.14) ln( λ/98 ) + 0.64 ± 0.07 results for 167 ’detected’ clusters with an intrinsic scatter σ_intr = 0.89 ± 0.05.