Baryonic Feedback Measurement From KV450 Cosmic Shear Analysis

While baryonic feedback is one of the most important astrophysical systematics that we need to address in order achieve precision cosmology, few weak lensing studies have directly measured its impact on matter power spectrum. We report measurement parameter with constraints lower and upper limits from cosmic shear. use public data Kilo-Degree Survey VISTA Infrared Galaxy spanning 450 deg$^2$. Estimating both cosmological parameters simultaneously, obtain $A_{\rm b}=1.01_{-0.85}^{+0.80}$, which shows a consistency dark matter-only (DMO) case at $\sim1.2~\sigma$ level tendency toward positive feedback; b}=0$ ($0.81$) value corresponds DMO (OWLS AGN) case. Despite this full constraint parameter, our $S_8~(\equiv \sigma_8 \sqrt{\Omega_m / 0.3})$ ($0.739^{+0.036}_{- 0.035}$) shifts by only $\sim6$% statistical error, compared previous measurement. When assume flat $\Lambda$CDM cosmology favored Nine-Year Wilkinson Microwave Anisotropy Probe (Planck) result, constrained be b}=1.21_{-0.54}^{+0.61}$ ($1.60_{-0.52}^{+0.53}$), excludes $\sim2.2~\sigma$ ($\sim3.1~\sigma$) level.