2025ApJS..279...22T

We utilized the R. Edelson & M. Malkan and D. Stern et al. selection techniques and other methods to identify active galactic nuclei (AGN) candidates that were monitored during the Kepler prime and K2 missions. Subsequent to those observations, we obtained 125 long-slit optical spectra with the Lick 3 m telescope, 58 spectra with the Palomar 5 m telescope, and three spectra with the Keck 10 m telescope to test these identifications. Of these 186 AGN candidates, 105 were confirmed as Type 1 AGN and 35 as Type 2 AGN, while the remaining 46 were found to have other identifications (e.g., stars and normal galaxies). This indicated an overall reliability of ∼75%, while the two main methods had much higher reliability, 87%-96%. The spectra indicated redshifts out to z = 3.4. Then, we examined the AGN sample properties through the Baldwin-Phillips-Terlevich diagram and compared the AGNs' spectral energy distributions with those from the literature. We found that our sample yielded the same AGN population as those identified through other methods, such as optical spectroscopy.