The XMM cluster survey: exploring scaling relations and completeness of the dark energy survey year 3 redMaPPer cluster catalogue

Upsdell, E. W.; Giles, P. A.; Romer, A. K.; Wilkinson, R.; Turner, D. J.; Hilton, M.; Rykoff, E.; Farahi, A.; Bhargava, S.; Jeltema, T.; Klein, M.; Bermeo, A.; Collins, C. A.; Ebrahimpour, L.; Hollowood, D.; Mann, R. G.; Manolopoulou, M.; Miller, C. J.; Rooney, P. J.; Sahlen, M.; Stott, J. P.; Viana, P. T. P.; Allam, S.; Alves, O.; Bacon, D.; Bertin, E.; Bocquet, S.; Brooks, D.; Burke, D. L.; Kind, M. C.; Carretero, J.; Costanzi, M.; da Costa, L. N.; Pereira, M. E. S.; De Vicente, J.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Everett, S.; Ferrero, I.; Frieman, J.; Garcia-Bellido, J.; Gerdes, D. W.; Gutierrez, G.; Hinton, S. R.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Marshall, J. L.; Mena-Fernandez, J.; Menanteau, F.; Miquel, R.; Mohr, J. J.; Ogando, R. L. C.; Pieres, A.; Raveri, M.; Rodriguez-Monroy, M.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; To, C.; Weaverdyck, N.; Weller, J.; Wiseman, P.

doi:10.1093/mnras/stad1220

We cross-match and compare characteristics of galaxy clusters identified in observations from two sky surveys using two completely different techniques. One sample is optically selected from the analysis of 3 years of Dark Energy Survey observations using the redMaPPer cluster detection algorithm. The second is X-ray selected from XMM observations analysed by the XMM Cluster Survey. The samples comprise a total area of 57.4 deg2, bounded by the area of four contiguous XMM survey regions that overlap the DES footprint. We find that the X-ray-selected sample is fully matched with entries in the redMaPPer catalogue, above λ > 20 and within 0.1 <0.9. Conversely, only 38 per cent of the redMaPPer catalogue is matched to an X-ray extended source. Next, using 120 optically clusters and 184 X-ray-selected clusters, we investigate the form of the X-ray luminosity-temperature (LX -TX ), luminosity-richness (LX -λ), and temperature-richness (TX -λ) scaling relations. We find that the fitted forms of the LX -TX relations are consistent between the two selection methods and also with other studies in the literature. However, we find tentative evidence for a steepening of the slope of the relation for low richness systems in the X-ray-selected sample. When considering the scaling of richness with X-ray properties, we again find consistency in the relations (i.e. LX -λ and TX -λ) between the optical and X-ray-selected samples. This is contrary to previous similar works that find a significant increase in the scatter of the luminosity scaling relation for X-ray-selected samples compared to optically selected samples.