Paper

A Cigale module tailored (not only) for Low-Luminosity AGN

X López López, Bertola, E, Baldi, R D, Lapi, A, Shankar, F, Laloux, B, Comastri, A, Acharya, N, Mountrichas, G, Bonoli, S, Musiimenta, B, I Muñoz Rodríguez, N Osorio Clavijo, López, I E, Brusa, M, Sengupta, D, Yang, G, Alexander, D M, Sala, L, Alonso Tetilla, A V

2024

Overview

The spectral energy distribution (SED) of low-luminosity active galactic nuclei (LLAGN) presents challenges due to their faint emissions and the complexity of their accretion processes. This study introduces a new CIGALE module tailored for LLAGN, combining the empirical \\(L_X\\)-\\(L_{12\\mu m}\\) relationship with physical models like advection-dominated accretion flows (ADAFs) and truncated accretion disks. This module yields a refined depiction of LLAGN emissions, and a mock analysis shows reliable parameter recovery, with only minor biases. We tested the module on a sample of 50 X-ray-detected local galaxies, including LINERs and Seyferts, where it demonstrated good estimation of bolometric luminosities, even in the presence of significant galaxy contamination. Notably, the previous X-ray module failed to provide AGN solutions for this sample, stressing the need for a novel approach. Comparisons with mid-luminosity AGN confirm the module's robustness and applicability to AGN up to \\(L_X\\) < \\(10^{45}\\) erg/s. We also expanded the X-ray to bolometric correction formula, making it applicable to AGN spanning ten orders of magnitude in luminosity, and revealing lower \\(k_X\\) values than typically assumed. Additionally, our analysis of the \\(\\alpha_{ox}\\) index, representing the slope between UV and X-ray emissions, uncovered trends that differ from those observed in high-luminosity AGN, suggesting a shift in accretion physics and photon production mechanisms in low-luminosity regimes. These results underscore the importance of a multiwavelength approach in AGN studies and reveal distinct behaviors in LLAGN compared to quasars. Our findings significantly advance the understanding of LLAGN and offer a comprehensive framework for future research aimed at completing the census of the AGN population.

• Publisher: Cornell University Library, arXiv.org
• Subject: Accretion disks / Active galactic nuclei / Alpha rays / Bolometers / Galaxies / Linings / Luminosity / Modules / Quasars / Spectral energy distribution / X-ray astronomy