A measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and DES ...

• Main Authors: Schiappucci, E., Bianchini, F., Aguena, M., Archipley, M., Balkenhol, L., Bleem, L. E., Chaubal, P., Crawford, T. M., Grandis, S., Omori, Y., Reichardt, C. L., Rozo, E., Rykoff, E. S., To, C., Abbott, T. M. C., Ade, P. A. R., Alves, O., Anderson, A. J., Andrade-Oliveira, F., Annis, J., Avva, J. S., Bacon, D., Benabed, K., Bender, A. N., Benson, B. A., Bernstein, G. M., Bertin, E., Bocquet, S., Bouchet, F. R., Brooks, D., Burke, D. L., Carlstrom, J. E., Rosell, A. Carnero, Kind, M. Carrasco, Carretero, J., Cecil, T. W., Chang, C. L., Chichura, P. M., Chou, T. -L., Costanzi, M., Cukierman, A., da Costa, L. N., Daley, C., de Haan, T., Desai, S., Dibert, K. R., Diehl, H. T., Dobbs, M. A., Doel, P., Doux, C.
• Format: Text
• Language: unknown
• Published: arXiv 2022
• Subjects: Cosmology and Nongalactic Astrophysics astro-ph.CO; FOS Physical sciences; South Pole; South pole
• Online Access: https://dx.doi.org/10.48550/arxiv.2207.11937; https://arxiv.org/abs/2207.11937

We infer the mean optical depth of a sample of optically-selected galaxy clusters from the Dark Energy Survey (DES) via the pairwise kinematic Sunyaev-Zel'dovich (kSZ) effect. The pairwise kSZ signal between pairs of clusters drawn from the DES Year-3 cluster catalog is detected at $4.1 σ$ in cosmic microwave background (CMB) temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the $\sim 1,400$ deg$^2$ of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise kSZ signal is $\barτ_e = (2.97 \pm 0.73) \times 10^{-3}$, while that inferred from the thermal SZ signal is $\barτ_e = (2.51 \pm 0.55^{\text{stat}} \pm 0.15^{\rm syst}) \times 10^{-3}$. The two measures agree at $0.6 σ$. We perform a suite of systematic checks to test the robustness of the analysis. ...