Time-resolved infrared emission spectra of naphthalene under gas phase laboratory and astrophysical conditions

► A complete modeling of time-dependent IR emission spectra of polyatomic molecules is achieved. ► The time scales covered range from the brief optical excitation to the long-time relaxation. ► The competition between infrared emission and unimolecular dissociation is taken into account. ► The possible effects of collisional relaxation in an inert gas are included by means of statistical modeling. ► Successful comparison with available astrochemical observations and laboratory experiments is reported.