The black hole--galaxy correlations of the 12,μm local active galactic nucleus sample: A NuSTAR perspective

The M--sigma correlation of inactive galaxies plays a crucial role in the estimation of the black hole mass ( in active galactic nuclei (AGNs). This correlation is used to calibrate the reverberation mapping (RM) method, which forms the basis of the single epoch method, the most-used technique to determine of broad-line AGNs. Furthermore, in narrow-line AGNs, the is often directly inferred from the M--sigma correlation. The main goal of this work was to test whether the M--sigma relation calibrated from inactive galaxies can be reliably applied to a local AGN population spanning Seyfert 1, Seyfert 2, and hidden broad-line region galaxies, and whether the resulting AGN relation has sufficient predictive power to be used as an indirect estimator. To this end, we used the 12,μm AGN sample, a local representative and largely unbiased sample. Since a substantial fraction of this sample has good quality νstar data, we estimated the of the sample with the X-ray scaling method, which works for any AGN accreting at a moderate or high level. The correlation of the 12,μm AGN sample is different from the one obtained with inactive galaxies, and it has a substantial scatter. Therefore, its predictive power for estimates is fairly limited. The correlation based on the 12,μm AGN sample is consistent with the analogous correlation obtained from a large sample of nearby type 1 AGNs but inconsistent with that of inactive galaxies. Finally, we found suggestive evidence that Seyfert 1 and hidden broad-line region galaxies have similar and systematically higher Eddington ratios than Seyfert 2 galaxies.