RT info:eu-repo/semantics/bachelorThesis T1 Halo mass measurements with the kinetic Sunyaev-Zel'dovich effect. A1 Isla Llave, Mónica Natalia A2 Plan Erasmus / Sicue AB In the past few years, several collaborations studying the Cosmic Microwave Background have usedthe kinetic Sunyaev-Zel’dovich (kSZ) effect to measure gas mass and total mass of galaxy clusters (Calafutet al., 2021; Vavagiakis et al., 2021). These assume the kSZ signal associated to the galaxy cluster isentirely caused by the ionised gas inside its virial radius, dismissing the kSZ effect caused by unboundelectrons that lie next to and along the same line of sight than the clusters’. This would introduce abias impacting the mass estimates made from kSZ measurements. This project is aimed at quantifyingthe free-electron contribution to the total kSZ signal along a line of sight towards a galaxy cluster/groupcharacterised by its mass and its redshift. Two methods have been employed: a semi-analytical method,which applies linear theory and uses theoretical models from Chaves-Montero et al. (2021), Tinker et al.(2010), and Vogelsberger et al. (2020); and a numerical method, using data from an N-body simulation atz = 0 provided by Prof. Dr. Ra´ul Angulo. The results obtained from both are qualitatively compatible,with the relative free-electron contribution being greater (30 − 40%) for lower mass halos (Mhalo ≲ 1013M⊙/h), and decreasing with mass (5 − 10% for Mhalo ≳ 1015 M⊙/h). The difference between the resultsobtained with the semi-analytical method and the simulation data, which is primarily seen in the growthcurve of the kSZ halo contribution as a function of halo mass, may have been caused by non-linear effectswhich have been neglected in the linear theory approach this project has followed, although current effortsare investigating more deeply the cause of this mismatch YR 2022 FD 2022 LK http://riull.ull.es/xmlui/handle/915/29072 UL http://riull.ull.es/xmlui/handle/915/29072 LA es DS Repositorio institucional de la Universidad de La Laguna RD 09-jul-2024