Event Title

Bayesian Statistics and Estimating Stellar Masses in the Blind Cosmology Challenge and the Dark Energy Survey

Session Number

R958

Advisor(s)

James Annis, Fermi National Accelerator Laboratory

Location

A-129

Start Date

28-4-2016 1:10 PM

End Date

28-4-2016 1:35 PM

Disciplines

Physics

Abstract

The purpose of this investigation was to apply the techniques and strategies developed on simulated data over the course of the summer on actual data from the Dark Energy Survey. Bayesian techniques were developed to measure the stellar masses of galaxy clusters through the use simulated data from the Blind Cosmology Challenge (BCC) using models derived from Simha et al (2014) and Conroy and Gunn’s FSPS. Our analysis of data from the BCC mirrors the results of the Canada France Legacy Survey for high mass galaxy clusters (clusters of at least 10^13 stellar masses). There is discrepancy at lower masses because the BCC underestimates the size of central galaxies in lower mass galaxies. We are currently awaiting results on our analysis of galaxies cataloged by the Redmapper galaxy catalogue and these results will be presented at IMSAloquium. We can conclude that Bayesian methods of analysis can provide accurate results when applied to live data. Additionally, since this Bayesian technique provides not the best fit value, but rather, the most likely value, our estimates for stellar mass could be useful as a proxy for the galaxy richness, a key variable when analyzing and modeling the cosmology of a cluster.


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Apr 28th, 1:10 PM Apr 28th, 1:35 PM

Bayesian Statistics and Estimating Stellar Masses in the Blind Cosmology Challenge and the Dark Energy Survey

A-129

The purpose of this investigation was to apply the techniques and strategies developed on simulated data over the course of the summer on actual data from the Dark Energy Survey. Bayesian techniques were developed to measure the stellar masses of galaxy clusters through the use simulated data from the Blind Cosmology Challenge (BCC) using models derived from Simha et al (2014) and Conroy and Gunn’s FSPS. Our analysis of data from the BCC mirrors the results of the Canada France Legacy Survey for high mass galaxy clusters (clusters of at least 10^13 stellar masses). There is discrepancy at lower masses because the BCC underestimates the size of central galaxies in lower mass galaxies. We are currently awaiting results on our analysis of galaxies cataloged by the Redmapper galaxy catalogue and these results will be presented at IMSAloquium. We can conclude that Bayesian methods of analysis can provide accurate results when applied to live data. Additionally, since this Bayesian technique provides not the best fit value, but rather, the most likely value, our estimates for stellar mass could be useful as a proxy for the galaxy richness, a key variable when analyzing and modeling the cosmology of a cluster.