The relation between the integrated Sunyaev-Zeldovich (SZ) y-decrement versus halo mass (Y-M) can potentially constrain galaxy formation models, if theoretical and observational systematics can be properly assessed. We investigate the Y−M relation in the SIMBA and IllustrisTNG-100 cosmological hydrodynamic simulations, quantifying the effects of feedback, line-of-sight projection, and beam convolution. We find that SIMBA’s AGN jet feedback generates strong deviations from self-similar expectations for the Y−Mrelation, especially at M500<1013M⊙. In SIMBA this is driven by suppressed in-halo y contributions owing to lowered halo baryon fractions. IllustrisTNG results more closely resemble SIMBA without jets. Projection of line-of-sight structures weakens these model differences slightly, but they remain significant at mostly group and lower halo masses. In contrast, beam smearing at Planckresolution makes the models indistinguishable, and both models appear to agree well with Planck data down to the lowest masses probed. We show that the arcminute resolution expected from forthcoming facilities would retain the differences between model predictions, and thereby provide strong constraints on AGN feedback.
Reference:
Understanding the Sunyaev-Zeldovich decrement versus halo mass using the SIMBA and TNG Simulations, Tianyi Yang, Yan-Chuan Cai, Weiguang Cui, Romeel Davé, John A. Peacock, Daniele Sorini, arXiv:2202.11430