A pan-chromatic view of the galaxy cluster XMMU J1230.3+1339 at z=0.975 - Observing the assembly of a massive system

Understand

We present a comprehensive galaxy cluster study of XMMU J1230.3+1339 based on a joint analysis of X-ray data, optical imaging and spectroscopy observations, weak lensing results, and radio properties for achieving a detailed multi-component view of this newly discovered system at z=0.975.

• We find an optically very rich and massive system with M200$\simeq$(4.2$\pm$0.8)$\times$10^14 M$\sun$, Tx$\simeq$5.3(+0.7--0.6)keV, and Lx$\simeq$(6.5$\pm$0.7)$\times$10^44 erg/s, for which various widely used mass proxies are measured and compared.
• We have identified multiple cluster-related components including a central fly-through group close to core passage with associated marginally extended 1.4GHz radio emission possibly originating from the turbulent wake region of the merging event.
• On the cluster outskirts we see evidence for an on-axis infalling group with a second Brightest Cluster Galaxy (BCG) and indications for an additional off-axis group accretion event.