Rotationally resolved photoelectron spectrum of the methyl radical in the vicinity of the photoionizing transition. The black curve is the experimental spectrum and the red one a simulation performed at 250 K and convolved with a Gaussian line shape (FWHM = 1 cm⁻¹), see text for details. The R and P branches are labeled by the N quantum number of the neutral species (total angular momentum excluding nuclear and electron spins).