Relativistic SZ temperatures and hydrostatic mass bias for massive clusters in the FLAMINGO simulations
Year: 2024
Type: article
Abstract: ABSTRACT The relativistic Sunyaev-Zel’dovich (SZ) effect can be used to measure intracluster gas temperatures independently of X-ray spectroscopy. Here, we use the large-volume FLAMINGO simulation suite to determine whether SZ y-weighted temperatures lead to more accurate hydrostatic mass estimates in massive ($M_{\rm 500c} \gt 7.5\times 10^{14}\, {\rm M}_{\odot }$) clusters than when using X-ray spectroscopic-like temperatures. We find this to be the case, on average. The median bias in the SZ mass at redshift zero is $\left\langle b \right\rangle \equiv 1-\left\langle M_{\rm 500c,hse}/M_{\rm 500c,true} \right\rangle = -0.05 \pm 0.01$, over 4 times smaller in magnitude than the X-ray spectroscopic-like case, $\left\langle b \right\rangle = 0.22 \pm 0.01$. However, the scatter in the SZ bias, $\sigma _{b} \approx 0.2$, is around 40 per cent larger than for the X-ray case. We show that this difference is strongly affected by clusters with large pressure fluctuations, as expected from shocks in ongoing mergers. Selecting the clusters with the best-fitting generalized NFW pressure profiles, the median SZ bias almost vanishes, $\left\langle b \right\rangle = -0.009 \pm 0.005$, and the scatter is halved to $\sigma _{b} \approx 0.1$. We study the origin of the SZ/X-ray difference and find that, at $R_{\rm 500c}$ and in the outskirts, SZ weighted gas better reflects the hot, hydrostatic atmosphere than the X-ray weighted gas. The SZ/X-ray temperature ratio increases with radius, a result we find to be insensitive to variations in baryonic physics, cosmology, and numerical resolution.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,012
Awards: G1259507762, Durham DiRAC-2 petascale facility, G1468651527, G1525616127, G1541806023, G1736745720, G1771230537, DiRAC-2.5 - the pathway to DiRAC Phase 3, G2073976794, G2076157637, G2240879383, G2309215924, G2368581224, G2566822479, G2843074508, G3149743720, G3403823835, G3641108176, G3680780005, G3718830055, G3911511115, G4022262583, G4251892262, G4831232377, G5660267321, G5997058474, G6181174915, DiRAC-2.5 DC - Operations 2017-2020, G6537386148, G6802598382, G6955735330, G6958025938, G7108246583, G7447190122, G7573294876, G7615445472, G7615492845, G7629755209, G7702914472, G7937591081, DiRAC: Memory Intensive 2.5y, G8150249736, G8695159654, G878803593, DiRAC: Memory Intensive 2.5x
OpenAlex ID: W4402574280