Role of ionizing background and galactic feedback on the redshift space clustering of OVI absorbers in hydrodynamical simulations

Abstract

We explore the effect of ionizing UV background (UVB) on the redshift space clustering of low-$\textit{z}$ ($\textit{z} \leq 0.5$) OVI absorbers using Sherwood simulations incorporating "WIND" (i.e. outflows driven by stellar feedback) only and "AGN+WIND" feedbacks. These simulations show a positive clustering signals up to a scale of 3 Mpc. We find that the effect of feedback is restricted to small scales (i.e $\leq$ 2 Mpc or 200 $\textit{kms}^{-1} $ at $\textit{z}$ ~ 0.3) and "WIND" only simulations produce stronger clustering signal compared to simulations incorporating "AGN+WIND" feedbacks. How clustering signal is affected by the assumed UVB depends on the feedback processes assumed. For the simulations considered here the effect of UVB is confined to even smaller scales (i.e <1 Mpc or $\approx 100\textit{kms}^{-1}$ at $\textit{z}$ ~ 0.3). These scales are also affected by exclusion caused by line blending. Therefore, our study suggests clustering at intermediate scales (i.e 1-2 Mpc for simulations considered here) together with the observed column density distribution can be used to constrain the effect of feedback in simulations.