The XMM Cluster Survey: optical analysis methodology and the first data release
Hilton, Matt; Stanford, S. A.; Stott, John P.; Mehrtens, Nicola; Edge, Alastair C.; Romer, A. Kathy; Sabirli, Kivanc; Davidson, Michael; Viana, Pedro T. P.; Collins, Chris A.; Kay, Scott T.; Liddle, Andrew R.; Mann, Robert G.; Miller, Christopher J.; Nichol, Robert C.; Edmondson, Edward M.; Wake, David; Maia, Marcio A. G.; Short, C. J.; Smith, Mathew; Hoyle, Ben; Hosmer, Mark; Sahlén, Martin; Burke, Claire; Lloyd-Davies, E. J.; Mayers, Julian A.; Benoist, Christophe; Rooney, Philip J.; Dubois, E. Naomi; Young, Owain; Christodoulou, L.; Watson, William A.; Harrison, Craig D.; Baruah, Leon; Deadman, Paul-James; West, Michael; Campbell, Heather C.; da Costa, Luiz; Ogando, Ricardo
United Kingdom, South Africa, United States, Spain, Finland, Portugal, Sweden, Chile, France, Brazil
Abstract
The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we present the first data release from the XMM Cluster Survey (XCS-DR1). This consists of 503 optically confirmed, serendipitously detected, X-ray clusters. Of these clusters, 256 are new to the literature and 357 are new X-ray discoveries. We present 463 clusters with a redshift estimate (0.06 < z < 1.46), including 261 clusters with spectroscopic redshifts. The remainder have photometric redshifts. In addition, we have measured X-ray temperatures (TX) for 401 clusters (0.4 < TX < 14.7 keV). We highlight seven interesting subsamples of XCS-DR1 clusters: (i) 10 clusters at high redshift (z > 1.0, including a new spectroscopically confirmed cluster at z= 1.01); (ii) 66 clusters with high TX (>5 keV) (iii) 130 clusters/groups with low TX (<2 keV) (iv) 27 clusters with measured TX values in the Sloan Digital Sky Survey (SDSS) ‘Stripe 82’ co-add region; (v) 77 clusters with measured TX values in the Dark Energy Survey region; (vi) 40 clusters detected with sufficient counts to permit mass measurements (under the assumption of hydrostatic equilibrium); (vii) 104 clusters that can be used for applications such as the derivation of cosmological parameters and the measurement of cluster scaling relations. The X-ray analysis methodology used to construct and analyse the XCS-DR1 cluster sample has been presented in a companion paper, Lloyd-Davies et al.