Speaker
Description
Low-luminosity active galactic nuclei (LLAGN) occupy the low-accretion, low-luminosity end of the AGN population, where jet activity and particle acceleration can be modest. A significant subset of them are LINERs, nearby galactic nuclei characterized by weakly ionized emission lines. The recent TeV detection of the LINER/LLAGN NGC 4278 therefore offers a rare opportunity to probe high-energy processes in this faint regime. Using MEGARA optical spectroscopy together with the LHAASO TeV results, we find that the large-scale ionized outflows in NGC 4278 cannot supply the energy needed to produce the TeV emission. Instead, contemporaneous Fermi-LAT and Swift data point to a compact nuclear accelerator, consistent with the observed variability and hard GeV spectrum. This indicates that the TeV photons originate in the innermost jet region, while the optical outflows trace larger-scale jet gas interactions that coexist but do not power the gamma rays. NGC 4278 thus becomes a benchmark for understanding high-energy activity in LINERs and a compelling nearby target for the Cherenkov Telescope Array Observatory, the next-generation facility for very high energy gamma-ray astronomy.