Spectral Energy Distribution Models for Low-luminosity Active Galactic
  Nuclei in LINERs
  Low-luminosity active galactic nuclei (LLAGNs) represent the bulk of the AGN
population in the present-day universe and they trace the low-level accreting
supermassive black holes. In order to probe the accretion and jet physical
properties in LLAGNs as a class, we model the broadband radio to X-rays
spectral energy distributions (SEDs) of 21 LLAGNs in low-ionization nuclear
emission-line regions (LINERs) with a coupled accretion-jet model. The
accretion flow is modeled as an inner ADAF outside of which there is a
truncated standard thin disk. We find that the radio emission is severely
underpredicted by ADAF models and is explained by the relativistic jet. The
origin of the X-ray radiation in most sources can be explained by three
distinct scenarios: the X-rays can be dominated by emission from the ADAF, or
the jet, or the X-rays can arise from a jet-ADAF combination in which both
components contribute to the emission with similar importance. For 3 objects
both the jet and ADAF fit equally well the X-ray spectrum and can be the
dominant source of X-rays whereas for 11 LLAGNs a jet-dominated model accounts
better than the ADAF-dominated model for the data. The individual and average
SED models that we computed can be useful for different studies of the nuclear
emission of LLAGNs. From the model fits, we estimate important parameters of
the central engine powering LLAGNs in LINERs, such as the mass accretion rate
and the mass-loss rate in the jet and the jet power - relevant for studies of
the kinetic feedback from jets.
