We quantify two main pathways through which baryonic physics biases cluster count cosmology. We create mock cluster samples that reproduce the baryon content inferred from X-ray observations. We link clusters to their counterparts in a dark matter-only universe, whose abundances can be predicted robustly, by assuming the dark matter density profile is not significantly affected by baryons. We derive weak lensing halo masses and infer the best-fitting cosmological parameters Ωm, S8 = σ8(Ωm/0.3)0.2, and w0 from the mock cluster sample. We find that because of the need to accommodate the change in the density profile due to the ejection of baryons, weak lensing mass calibrations are only unbiased if the concentration is left free when fitting the reduced shear with NFW profiles. However, even unbiased total mass estimates give rise to biased cosmological parameters if the measured mass functions are compared with predictions from dark matter-only simulations. This bias dominates for haloes with $m_\mathrm{500c} \lt 10^{14.5} \, \rm h^{-1} \, \mathrm{M_\odot }$. For a stage IV-like cluster survey without mass estimation uncertainties, an area $\approx 15\,000 \, \mathrm{deg^2}$ and a constant mass cut of $m_\mathrm{200m,min} = 10^{14} \,\rm h^{-1} \, \mathrm{M_\odot }$, the biases are $-11 \pm 1 \, \mathrm{per\, cent}$ in Ωm, $-3.29 \pm 0.04 \, \mathrm{per\, cent}$ in S8, and $9 \pm 1.5 \, \mathrm{per\, cent}$ in w0. The statistical significance of the baryonic bias depends on how accurately the actual uncertainty on individual cluster mass estimates is known. We suggest that rather than the total halo mass, the (re-scaled) dark matter mass inferred from the combination of weak lensing and observations of the hot gas, should be used for cluster count cosmology.

中文翻译：

---

重子如何显着偏向集群计数宇宙学

我们量化了重子物理学偏向集群计数宇宙学的两条主要途径。我们创建模拟集群样本，重现从 X 射线观测中推断出的重子含量。我们通过假设暗物质密度分布不​​受重子的显着影响，将星团与其在只有暗物质的宇宙中的对应物联系起来，可以可靠地预测其丰度。我们推导出弱透镜晕质量，并从模拟星团样本中推断出最适合的宇宙学参数 Ωm、S8 = σ8(Ωm/0.3)0.2 和 w0。我们发现，由于需要适应由于重子的喷射而导致的密度分布的变化，弱透镜质量校准只有在将减少的剪切与 NFW 分布拟合时保持自由浓度时才是无偏的。然而，如果将测量的质量函数与仅暗物质模拟的预测进行比较，即使是无偏的总质量估计也会产生有偏的宇宙学参数。这种偏差在具有 $m_\mathrm{500c} \lt 10^{14.5} \, \rm h^{-1} \, \mathrm{M_\odot }$ 的晕圈中占主导地位。对于没有质量估计不确定性的类似 IV 阶段的集群调查，面积 $\约 15\,000 \, \mathrm{deg^2}$ 和 $m_\mathrm{200m,min} = 10^ 的恒定质量切割{14} \,\rm h^{-1} \, \mathrm{M_\odot }$, 偏差为 $-11 \pm 1 \, \mathrm{per\, cent}$ in Ωm, $-3.29在 S8 中 \pm 0.04 \, \mathrm{per\, cent}$，在 w0 中 $9 \pm 1.5 \, \mathrm{per\, cent}$。重子偏差的统计显着性取决于对单个集群质量估计的实际不确定性的准确程度。我们建议，而不是总晕质量，