Optimal 1D Ly$\alpha$ Forest Power Spectrum Estimation -- II. KODIAQ, SQUAD & XQ-100

Understand

We measure the 1D Ly$\,\alpha$ power spectrum $P_\mathrm{1D}$ from Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ), The Spectral Quasar Absorption Database (SQUAD) and XQ-100 quasars using the optimal quadratic estimator.

• We combine KODIAQ and SQUAD at the spectrum level, but perform a separate XQ-100 estimation to control its large resolution corrections in check.
• Our final analysis measures $P_\mathrm{1D}$ at scales $k<0.1\,$s$\,$km$^{-1}$ between redshifts $z=$ 2.0 -- 4.6 using 538 quasars.
• This sample provides the largest number of high-resolution, high-S/N observations; and combined with the power of optimal estimator it provides exceptional precision at small scales.