The XXL survey: XLVI. Forward cosmological analysis of the C1 cluster sample

Understand

We present the forward cosmological analysis of an $XMM$ selected sample of galaxy clusters out to a redshift of unity.

• Following our previous 2018 study based on the dn/dz quantity alone, we perform an upgraded cosmological analysis of the same XXL C1 cluster catalogue (178 objects), with a detailed account of the systematic errors.
• We follow the ASpiX methodology: the distribution of the observed X-ray properties of the cluster population is analysed in a 3D observable space (count rate, hardness ratio, redshift) and modelled as a function of cosmology.
• Compared to more traditional methods, ASpiX allows the inclusion of clusters down to a few tens of photons.