Detecting preheating in proto-clusters with Lyman-$\alpha$ Forest Tomography

Abstract

Studies of low redshift galaxy clusters suggest the intra-cluster medium (ICM) has experienced non-gravitational heating during the formation phase of the clusters. Using simple phenomenological heating prescriptions, we simulate the effect of this preheating of the nascent ICM in galaxy proto-clusters and examine its effect on Lyman-$\alpha$ (Ly$\alpha$) forest tomographic maps. We analyse a series of cosmological zoom-in simulations of proto-clusters within the framework of the Ly$\alpha$ transmission-dark matter (DM) density distribution. We find that the more energy is injected into the proto-ICM at $z$ = 3, the more the distribution at high DM density tilts towards higher Ly$\alpha$ transmission. This effect has been confirmed in both low-resolution simulations adopting a preheating scheme based on entropy floors, as well as in higher-resolution simulations with another scheme based on energy floors. The evolution of the slope of this distribution is shown to vary with redshift. The methodology developed here can be applied to current and upcoming Ly$\alpha$ forest tomographic survey data to help constrain feedback models in galaxy proto-clusters.