The Circumgalactic Medium from the CAMELS Simulations: Forecasting Constraints on Feedback Processes from Future Sunyaev–Zeldovich Observations

Abstract

It is important to understand the cycle of baryons through the circumgalactic medium (CGM) in the context of galaxy formation and evolution. In this study, we forecast constraints on the feedback processes heating the CGM with current and future Sunyaev–Zeldovich (SZ) observations. To constrain these processes, we use a suite of cosmological simulations, the Cosmology and Astrophysics with MachinE Learning Simulations (CAMELS). CAMELS varies four different feedback parameters of two previously existing hydrodynamical simulations, IllustrisTNG and SIMBA. We capture the dependences of SZ radial profiles on these feedback parameters with an emulator, calculate their derivatives, and forecast future constraints on these feedback parameters from upcoming experiments. We find that for a galaxy sample similar to what would be obtained with the Dark Energy Spectroscopic Instrument at the Simons Observatory, all four feedback parameters can be constrained (some within the 10% level), indicating that future observations will be able to further restrict the parameter space for these subgrid models. Given the modeled galaxy sample and forecasted errors in this work, we find that the inner SZ profiles contribute more to the constraining power than the outer profiles. Finally, we find that, despite the wide range of parameter variation in active galactic feedback in the CAMELS simulation suite, we cannot reproduce the thermal SZ signal of galaxies selected by the Baryon Oscillation Spectroscopic Survey as measured by the Atacama Cosmology Telescope.

A Multi-Wavelength, Multi-Model Exploration of How Feedback Disrupts Gaseous Atmospheres

“…The resulting impact on the power spectrum of the cosmic matter correlation function (which is an essential measure for cosmological parameter estimation) is to increase power on scales out to which feedback can substantially redistribute the baryons. However, the SIMBA jet speed variations have the opposite effect: Increased jet speed reduces the density and pressure of the CGM [8]. Not only does every observable CGM property decrease significantly in Figure 2, but the electron density maps in Figure 1 take on a smoothed appearance.…”

“…For example, Moser et al ( 2022) [8] found that increasing the IllustrisTNG stellar feedback input energy raised the density and pressure of the CGM as measured via the kinetic and thermal S-Z effects. Likewise, the signal of every observable CGM feature in Figure 2 increases from run 1P_3_n5 to run 1P_3_0.…”

“…[13]). Interestingly, Moser et al (2022) [8] concluded that despite the wide range of feedback strengths in the CAMELS simulations, they cannot reproduce the exceedingly high pressures and high densities observed outside the virial radius of group-sized halos ([9] [10]). Indeed, groupsized (10 13 −10 14 M ⊙ ) halos have multiple properties that are not well reproduced by the current generation of flagship cosmological simulations like IllustrisTNG, SIMBA, EAGLE, and ROMULUS [14].…”

Inferring the impact of feedback on the matter distribution using the Sunyaev Zel'dovich effect: Insights from CAMELS simulations and ACT+DES data

“…Indeed, several works using both data (e.g Pandey et al 2019Pandey et al , 2022Gatti et al 2022a) and simulations (e.g. Scannapieco et al 2008;Bhat-tacharya et al 2008;Moser et al 2022;Wadekar et al 2022) have shown that the tSZ signal from low-mass (group scale) halos is sensitive to feedback. Excitingly, the sensitivity of tSZ measurements is expected to increase dramatically in the near future due to high-sensitivity CMB measurements from e.g.…”

“…Two recent works - Moser et al (2022) and Wadekar et al (2022) -have used the CAMELS simulations to explore the information content of the tSZ signal for constraining feedback. These works focus on the ability of tSZ observations to constrain the parameters of subgrid feedback models in hydrodynamical simulations.…”