X-ray characterisation of the massive galaxy cluster CIG J104803.7+313843 at z=0.76 with XMM-Newton

We present the characterisation of the massive cluster C1G J104803.7+313843 at z = 0.76 performed using a serendipitous XMM-Newton observation. High redshift and massive objects represent an ideal laboratory to benchmark our understanding of how clusters form and assembly formation is mainly driven by gravity. Leveraging the high throughput of XMM-Newton we were firstly able to determine the redshift of the object, shedding light on ambiguous photometric redshift associations. We investigated the morphology of this cluster which shows signs of merging activities in the outskirts and a flat core. We also measured the radial density profile up to R-500. With these quantities in hand, we were able to determine the mass, M-500 = 5.64(-0.62)(+0.79)( )x 10(14) M-circle dot, using the Y-X proxy. This quantity improves the previous measurement of the mass of this object by a factor of similar to 3.5. The characterisation of one cluster at such a mass and redshift regime is fundamental as these objects are intrinsically rare, with the number of objects discovered so far being less than similar to 25. Our study highlights the importance of using X-ray observations in combination with ancillary multi-wavelength data to improve our understanding of high-z and massive clusters.