To identify Auger-excited intraband emission, it is necessary to demonstrate that the observed emission: i) occurs after interband absorption, but ii) is caused by intraband rather than interband recombination. In the present article, we describe a methodical examination of the PL of an AuNF film with varying excitation wavelengths. By measuring the photoluminescence excitation (PLE) spectrum, we isolated the absorption processes that eventually result in emission. The PLE spectrum unambiguously establishes that only interband absorption leads to emission. In addition, we used the excitation wavelength dependent PL spectra to study the intrinsic emission process, isolated from the enhancement by the LSPR.