Exploring the Partially-obscured BLR and Partially-covered NLR

TL;DR

This study investigates the geometry of obscuring material in AGNs, revealing that partially obscured quasars are common and that the reddening material often lies between the BLR and NLR, impacting AGN unification models.

Contribution

It provides new statistical insights into the distribution of obscuring material and the location of reddening in AGNs, especially in partially obscured quasars.

Findings

Partially obscured quasars are as common as normal quasars.

Reddening material is mostly located between the BLR and NLR.

Inner NLR emission lines can be covered by the torus.

Abstract

We have conducted a series of investigations on the geometry of the reddening material in AGNs, which have important implications to the AGN unification and SMBH demography. According to our statistics of partially obscured quasars, we found that SMBHs in partially obscured type/phase (i.e., intermediate type) are at least as abundant as normal quasars in the local Universe; the reddening material in most objects are located in between the BLR and NLR. According to our comparison of narrow lines in type 1 and 2 AGNs, we found that for high-ionization or high-critical density narrow lines (e.g. OIII 5007, Balmer lines and FeII) a significant fraction of the emission arises from the inner dense part of the NLR; this inner NLR is located very close to the central engine and thus can be covered by the torus.