Randomized trial determines mass function of galaxy clusters, suggesting implications for cosmological models.
Key Points
The aim is to determine the mass function of galaxy clusters using optical and X-ray data.
Utilized recent optical and X-ray observations of galaxy clusters to derive the mass function.
Extended the mass function to include small groups of galaxies.
Analyzed the resulting mass function across a range from M ~ 10^12^ to >= 10^15^ h^-1^ M_sun_.
The mass function was consistent across optical and X-ray measurements within expected uncertainties.
The mass function is analytically expressed as n(>M) = 4 X 10^-5^(M/M^*^)^-1^ exp (-M/M^*) h^3^ Mpc^-3^ with M^*^ = (1.8 +/- 0.3) x 10^14^ h^-1^ M_sun_.
Observations show inconsistency with standard ({OMEGA}= 1) CDM models while aligning with low-density ({OMEGA} ~ 0.25) models.