Zoom in on 51 channels around the H_α (left) and H_β (right) lines of the YSES1 b spectrum estimates, from stellar halo subtraction, both with the SGF (in blue) and LPM (in orange) methods. The horizontal dots indicate the zero-flux level, i.e., the theoretical flux lower bound. Colored areas delimit the 1-σ confidence intervals with regard to noise. Dotted Gaussians are fitted to the lines to estimate their main parameters (presented in the legend, with confidence intervals derived from Gaussian fits to the lower and upper bounds of those of the spectrum estimates).