Galaxy clusters at 0.6-z-1.4 in the UKIDSS ultra deep survey early data release

We present the first cluster catalogue extracted from the UKIRT Infrared Deep Sky Survey Early Data Release. The catalogue is created using UKIDSS Ultra Deep Survey infrared J and K data combined with 3.6 µm and 4.5 µm Spitzer bands and optical BV Rizimaging from the Subaru Telescope over 0.5 square degrees in the Subaru XMM-Newton Deep Field. We have created a new cluster-detection algorithm, based on the Friends-Of-Friends and Voronoi Tessellation methods, which utilises probability distribution functions derived from a photometric redshift analysis. We employ mock catalogues to understand the selection effects and contamination associated with the algorithm. The cluster catalogue contains 13 clusters at redshifts 0.61 6 z 6 1.39 with luminosities 10L ∗ � Ltot � 50L ∗ , corresponding to masses 5 × 10 13 M⊙ � Mcluster � 3 × 10 14 M⊙ for M/M ⊙ L/L⊙ = 75h. The measured sky surface density of � 10 deg −2 for high-redshift (z = 0.5 1.5), massive (> 10 14 M⊙) clusters is precisely in line with theoretical predictions presented by Kneissl et al. (2001).