Compton-thick AGN in the NuSTAR Era X: Analysing seven local CT-AGN candidates

Abstract

Context. We present the broad-band X-ray spectral analysis (0.6–50 keV) of seven Compton-thick active galactic nuclei (CT-AGN; line-of-sight (LOS) column density > 1024 cm−2) candidates selected from the Swift-BAT 100 month catalogue using archival NuSTAR data. Aims. We aim to obtain a complete census of the heavily obscured AGN in the local Universe (z < 0.05). Methods. This work is in continuation of the ongoing research of the Clemson-INAF group to classify CT-AGN candidates at redshift z < 0.05 using physically motivated torus models. Results. Our results confirm that three out of seven targets are bona fide CT-AGN. Adding our results to the previously analysed sources using NuSTAR data, we increase the population of bona fide CT-AGN by ∼9%, bringing the total number to 35 out of 414 AGN. We also performed a comparative study using MYTorus and borus02 on the spectra in our sample, finding that both physical models are strongly consistent in the parameter space of LOS column density and photon index. Furthermore, we also investigate the clumpiness of the torus clouds by separately computing the LOS and average torus column densities in each of the seven sources. Adding our results to all the previous 48 CT-AGN candidates analysed by the Clemson-INAF research team for which NuSTAR observations are available, we find that 78% of the sources are likely to have a clumpy distribution of the obscuring material surrounding the accreting supermassive black hole.