SIMBAD references

We study the relation of optical/UV and X-ray emission in the low luminosity active galactic nuclei (LLAGNs), using a sample of 49 sources including 28 local Seyfert galaxies and 21 low-ionization nuclear emission-line regions with optical/UV spectral luminosity at wavelength λ = 2500 Å, 23.0 ≤ log L_ν(2500 Å)_(erg/s/Hz) ≤ 27.7, and X-ray spectral luminosity at 2 keV, 20.5 ≤ log L_ν(2 keV)_ ≤ 25.3. Strong correlations are found between the X-ray luminosity and the optical/UV-to-X-ray index, α_ox, with the optical/UV luminosity, with slopes very similar to the findings for the luminous AGNs in previous works. The correlation between α_ox and L_ν(2 keV)_is very weak, as is that found for the luminous AGNs in the majority of previous similar works. We also study the relation between α_ox and the Eddington ratio L_bol/L_Eddfor our sample and find a significant anti-correlation for the sources with L_bol/L_Edd ≲ 10^–3, which is opposite to the correlation between the two variables for the luminous AGNs. Using the advection-dominated accretion flow (ADAF) model, we roughly reproduce this anti-correlationship for the two variables for the LLAGNs. This result strongly supports the ADAF as a candidate for the accretion mode in LLAGNs.