Measurement of the splashback feature around SZ-selected Galaxy clusters with DES, SPT, and ACT

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Shin, T, Adhikari, S, Baxter, E J, Chang, C, Jain, B, Battaglia, N, Bleem, L, Bocquet, S, DeRose, J, Gruen, D, Hilton, M, Kravtsov, A, McClintock, T, Rozo, E, Rykoff, E S, Varga, T N, Wechsler, R H, Wu, H, Zhang, Z, Aiola, S, Allam, S, Bechtol, K, Benson, B A, Bertin, E, Bond, J R, Brodwin, M, Brooks, D, Buckley-Geer, E, Burke, D L, Carlstrom, J E, Carnero Rosell, A, Carrasco Kind, M, Carretero, J, Castander, F J, Choi, S K, Cunha, C E, Crawford, T M, da Costa, L N, De Vicente, J, Desai, S, Devlin, M J, Dietrich, J P, Doel, P, Dunkley, J, Eifler, T F, Evrard, A E, Flaugher, B, Fosalba, P, Gallardo, P A, García-Bellido, J
• Other Authors: Spanish MultiDark Consolider, U.S. Department of Energy, National Science Foundation, Science and Technology Facilities Council, Higher Education Funding Council for England, University of Illinois at Urbana-Champaign, University of Chicago, Ohio State University, Financiadora de Estudos e Projetos, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Ministério da Ciência, Tecnologia e Inovação, Deutsche Forschungsgemeinschaft, Argonne National Laboratory, University of Cambridge, University College London, University of Edinburgh, Lawrence Berkeley National Laboratory, University of Michigan, University of Nottingham, University of Pennsylvania, University of Portsmouth, Stanford University, University of Sussex, Ministry of Ecomony and Competitiveness, European Union, European Union’s Seventh Framework Program, European Research Council, Australian Research Council, Gordon and Betty Moore Foundation, National Aeronautics and Space Administration
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2019
• Subjects: South Pole; South pole
• Online Access: http://dx.doi.org/10.1093/mnras/stz1434; http://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stz1434/28701509/stz1434.pdf; http://academic.oup.com/mnras/article-pdf/487/2/2900/28830183/stz1434.pdf

ABSTRACT We present a detection of the splashback feature around galaxy clusters selected using the Sunyaev–Zel’dovich (SZ) signal. Recent measurements of the splashback feature around optically selected galaxy clusters have found that the splashback radius, rsp, is smaller than predicted by N-body simulations. A possible explanation for this discrepancy is that rsp inferred from the observed radial distribution of galaxies is affected by selection effects related to the optical cluster-finding algorithms. We test this possibility by measuring the splashback feature in clusters selected via the SZ effect in data from the South Pole Telescope SZ survey and the Atacama Cosmology Telescope Polarimeter survey. The measurement is accomplished by correlating these cluster samples with galaxies detected in the Dark Energy Survey Year 3 data. The SZ observable used to select clusters in this analysis is expected to have a tighter correlation with halo mass and to be more immune to projection effects and aperture-induced biases, potentially ameliorating causes of systematic error for optically selected clusters. We find that the measured rsp for SZ-selected clusters is consistent with the expectations from simulations, although the small number of SZ-selected clusters makes a precise comparison difficult. In agreement with previous work, when using optically selected redMaPPer clusters with similar mass and redshift distributions, rsp is ∼2σ smaller than in the simulations. These results motivate detailed investigations of selection biases in optically selected cluster catalogues and exploration of the splashback feature around larger samples of SZ-selected clusters. Additionally, we investigate trends in the galaxy profile and splashback feature as a function of galaxy colour, finding that blue galaxies have profiles close to a power law with no discernible splashback feature, which is consistent with them being on their first infall into the cluster.