Derivation of the Hubble parameter using galaxy clusters

[摘要] In this work we describe a possible way to use X-ray and microwave observations of nearby galaxy clusters to derive the value of the Hubble constant, that parametrises the expansion rate of the Universe. We provide a brief introduction to the Sunyaev-Zel'dovich effect that allows to detect galaxy clusters at microwave frequencies, and the method to combine it with X-ray observables. We emphasize what kind of considerations should be done when applying the method on real data and study the effect of the geometry of the clusters on the final result.

[发布机构] Dipartimento di Fisica, Universita di Roma tor Vergata, Via della Ricerca Scientifica 1, Roma; I-00133, Italy^1;Sezione INFN Roma 2, via della Ricerca Scientifica 1, Roma; I-00133, Italy^2;Harvard Smithsonian Centre for Astrophysics, 60 Garden Street, Cambridge; MA; 02138, United States^3

[关键词] Expansion rate;Galaxy clusters;Hubble constant;Microwave observations;Sunyaev-Zel'dovich effect