Simulation-based marginal likelihood for cluster strong lensing cosmology

Autor:	Killedar, Madhura, Borgani, Stefano, Fabjan, Dunja, Dolag, Klaus, Granato, Gian Luigi, Meneghetti, Massimo, Planelles, Susana, Ragone-Figueroa, Cinthia
Rok vydání:	2015
Předmět:	Astrophysics - Cosmology and Nongalactic Astrophysics Astrophysics - Instrumentation and Methods for Astrophysics Physics - Data Analysis Statistics and Probability Statistics - Applications
Druh dokumentu:	Working Paper
DOI:	10.1093/mnras/stx2262
Popis:	Comparisons between observed and predicted strong lensing properties of galaxy clusters have been routinely used to claim either tension or consistency with $\Lambda$CDM cosmology. However, standard approaches to such cosmological tests are unable to quantify the preference for one cosmology over another. We advocate approximating the relevant Bayes factor using a marginal likelihood that is based on the following summary statistic: the posterior probability distribution function for the parameters of the scaling relation between Einstein radii and cluster mass, $\alpha$ and $\beta$. We demonstrate, for the first time, a method of estimating the marginal likelihood using the X-ray selected $z>0.5$ MACS clusters as a case in point and employing both N-body and hydrodynamic simulations of clusters. We investigate the uncertainty in this estimate and consequential ability to compare competing cosmologies, that arises from incomplete descriptions of baryonic processes, discrepancies in cluster selection criteria, redshift distribution, and dynamical state. The relation between triaxial cluster masses at various overdensities provide a promising alternative to the strong lensing test. Comment: 15 pages, 6 figures, 1 table, accepted to MNRAS
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1507.05617 Zobrazit plný text záznamu View this record from Arxiv