Biases in the estimation of velocity dispersions and dynamical masses for galaxy clusters

Autor: Ferragamo A., Rubiño-Martín J.A., Betancort-Rijo J., Munari E., Sartoris B., Barrena R.
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: EPJ Web of Conferences, Vol 228, p 00011 (2020)
Druh dokumentu: article
ISSN: 2100-014X
DOI: 10.1051/epjconf/202022800011
Popis: Using a set of 73 numerically simulated galaxy clusters, we have characterised the statistical and physical biases for three velocity dispersion and mass estimators, namely biweight, gapper and standard deviation, in the small number of galaxies regime (Ngal ≤ 75), both for the determination of the velocity dispersion and the dynamical mass of the clusters via the σ–M relation. These results are used to define a new set of unbiased estimators, that are able to correct for those statistical biases. By applying these new estimators to a subset of simulated observations, we show that they can retrieve bias-corrected values for both the mean velocity dispersion and the mean mass.
Databáze: Directory of Open Access Journals