http://arxiv.org/abs/2201.12591

We carry out a thermal energy census of hot baryons at $z < 1$, by cross-correlating the Planck MILCA y-map with over 40 DESI galaxy cluster/group subsamples constructed from the Yang et. al (2021) catalog. In our investigation, we select 0.8 million clusters/groups with richness $\geq 5$ and estimated halo mass $\geq 10^{13} M_\odot/h$. The detection of the thermal Sunyaev-Zel’dovich (tSZ) effect is significant in the investigated clusters/groups. (1) The total measurement S/N of the one-halo term is 65. We constrain the $Y-M$ relation over the halo mass range of $10^{13}-10^{15} M_\odot/h$. We find $Y\propto M^{\alpha}$ with $\alpha= 1.8$ at $z=0.14$ and $\alpha=2.1$ at $z=0.75$. The total thermal energy of gas bound to clusters/groups increases from $0.11 \rm meV/cm^3$ at $z=0.14$ to $0.23 \rm meV/cm^3$ at $z=0.75$. (2) The two-halo term measurement constrains the bias-weighted electron pressure $\langle b_yP_e \rangle$. We find that $\langle b_yP_e \rangle$ (in unit of $\rm meV/cm^3$) increases from $0.25\pm 0.03$ at $z=0.14$ to $0.55\pm 0.04$ at $z=0.75$. These results lead to several implications. (i) The hot gas fraction $f_{\rm gas}$ in clusters/groups monotonically increase with halo mass, where $f_{\rm gas}$ of a $10^{14} M_\odot/h$ halo is $\sim 50\%$ ($20\%$) of the cosmic mean at $z=0.14\ (0.75)$. (ii) By comparing the 1h- and 2h-terms, we constrain the thermal energy of unbound gas. (iii) The above results lead to a suppression of matter and weak lensing power spectrum. At $l=10^3 \ (10^4)$, the suppression is $\sim 7\%\ (17\%)$ for source galaxies at $z_s=1$. These implications are potentially important for gastrophysics and cosmology, although they suffer from uncertainties in measurements (Planck resolution, cluster mass/redshift determination, etc) and gas modeling to be further investigated.

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Z. Chen, P. Zhang and X. Yang
Tue, 1 Feb 22
54/73

Comments: 16 pages, 13 figures