The first building block to use galaxy clusters in astrophysics and cosmology is the accurate determination of their mass. Two of the most well-regarded direct mass estimators are based on weak lensing (WL) determinations or X-ray analyses assuming hydrostatic equilibrium (HE). By comparing these two mass measurements in samples of rich clusters, we determined the intrinsic scatters, Σ<inf>WL</inf> ~ 15 per cent forWL masses and Σ<inf>HE</inf> ~ 25 per cent for HE masses. The certain assessment of the bias is hampered by differences as large as ~40 per cent in either WL or HE mass estimates reported by different groups. If the intrinsic scatter in the mass estimate is not considered, the slope of any scaling relation 'observable-mass' is biased towards shallower values, whereas the intrinsic scatter of the scaling is overestimated.
Sereno, M., Ettori, S. (2015). Comparing masses in literature (CoMaLit) - I. Bias and scatter in weak lensing and X-ray mass estimates of clusters. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 450(4), 3633-3648 [10.1093/mnras/stv810].
Comparing masses in literature (CoMaLit) - I. Bias and scatter in weak lensing and X-ray mass estimates of clusters
SERENO, MAURO;
2015
Abstract
The first building block to use galaxy clusters in astrophysics and cosmology is the accurate determination of their mass. Two of the most well-regarded direct mass estimators are based on weak lensing (WL) determinations or X-ray analyses assuming hydrostatic equilibrium (HE). By comparing these two mass measurements in samples of rich clusters, we determined the intrinsic scatters, ΣI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.