Shocks in the stacked Sunyaev-Zel'dovich profiles of clusters II: Measurements from SPT-SZ + Planck Compton-y map

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Anbajagane, D., Chang, C., Jain, B., Adhikari, S., Baxter, E. J., Benson, B. A., Bleem, L. E., Bocquet, S., Calzadilla, M. S., Carlstrom, J. E., Chang, C. L., Chown, R., Crawford, T. M., Crites, A. T., Cui, W., de Haan, T., Di Mascolo, L., Dobbs, M. A., Everett, W. B., George, E. M., Grandis, S., Halverson, N. W., Holder, G. P., Holzapfel, W. L., Hrubes, J. D., Lee, A. T., Luong-Van, D., McDonald, M. A., McMahon, J. J., Meyer, S. S., Millea, M., Mocanu, L. M., Mohr, J. J., Natoli, T., Omori, Y., Padin, S., Pryke, C., Reichardt, C. L., Ruhl, J. E., Saro, A., Schaffer, K. K., Shirokoff, E., Staniszewski, Z., Stark, A. A., Vieira, J. D., Williamson, R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Royal Astronomical Society 2022
• Subjects: galaxies: clusters: intracluster medium; large-scale structure of Universe; Space and Planetary Science; Astronomy and Astrophysics; South pole
• Online Access: https://doi.org/10.1093/mnras/stac1376

We search for the signature of cosmological shocks in stacked gas pressure profiles of galaxy clusters using data from the South Pole Telescope (SPT). Specifically, we stack the latest Compton-y maps from the 2500 deg² SPT-SZ survey on the locations of clusters identified in that same data set. The sample contains 516 clusters with mean mass〈M₂₀₀ₘ〉= 10^(14.9) M_⊕ and redshift〈z〉= 0.55. We analyse in parallel a set of zoom-in hydrodynamical simulations from the three hundred project. The SPT-SZ data show two features: (i) a pressure deficit at R/R₂₀₀ₘ = 1.08 ± 0.09, measured at 3.1σ significance and not observed in the simulations, and; (ii) a sharp decrease in pressure at R/R₂₀₀ₘ = 4.58 ± 1.24 at 2.0σ significance. The pressure deficit is qualitatively consistent with a shock-induced thermal non-equilibrium between electrons and ions, and the second feature is consistent with accretion shocks seen in previous studies. We split the cluster sample by redshift and mass, and find both features exist in all cases. There are also no significant differences in features along and across the cluster major axis, whose orientation roughly points towards filamentary structure. As a consistency test, we also analyse clusters from the Planck and Atacama Cosmology Telescope Polarimeter surveys and find quantitatively similar features in the pressure profiles. Finally, we compare the accretion shock radius (R_(sh,acc)) with existing measurements of the splashback radius (Rₛₚ) for SPT-SZ and constrain the lower limit of the ratio, R_(sh,acc)/Rₛₚ > 2.16 ± 0.59. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) Received: 23 November 2021. Revision received: 26 April 2022. Accepted: 09 May 2022. ...