Comparison of the astronomical spectrum (panel a) and simulations of the dyad (other panels) of ( electronic state) for different rotational temperatures (500 K, 700 K, and 900 K in panels b, c, and d, respectively). A zoom into the Q-branch is presented on the right-hand side of the figure. All simulations have been performed using the best-fit parameters (Table 1) and convolved with a Gaussian line shape (FWHM = 0.4 cm⁻¹).