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Coronal-Line Forest AGN: the best view of the inner edge of the AGN torus?

1 Pith paper cite this work, alongside 50 external citations. Polarity classification is still indexing.

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50 external citations · Pith
abstract

We introduce Coronal-Line Forest Active Galactic Nuclei (CLiF AGN), AGN which have a rich spectrum of forbidden high-ionization lines (FHILs, e.g. [FeVII], [FeX] and [NeV]), as well as relatively strong narrow ($\sim$300 km s$^{-1}$) H$\alpha$ emission when compared to the other Balmer transition lines. We find that the kinematics of the CLiF emitting region are similar to those of the forbidden low-ionization emission-line (FLIL) region. We compare emission line strengths of both FHILs and FLILs to CLOUDY photoionization results and find that the CLiF emitting region has higher densities (10$^{4.5}$ $<$ n$_H$ $<$ 10$^{7.5}$ cm$^{-3}$) when compared to the FLIL emitting region (10$^{3.0}$ $<$ n$_H$ $<$ 10$^{4.5}$ cm$^{-3}$). We use the photoionization results to calculate the CLiF regions radial distances (0.04 $<$ R$_{CLiF}$ $<$ 32.5 pc) and find that they are comparable to the dust grain sublimation distances (0.10 $<$ R$_{SUB}$ $<$ 4.3 pc). As a result we suggest that the inner torus wall is the most likely location of the CLiF region, and the unusual strength of the FHILs is due to a specific viewing angle giving a maximal view of the far wall of the torus without the continuum being revealed.

fields

astro-ph.GA 1

years

2026 1

verdicts

UNVERDICTED 1

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Showing 1 of 1 citing paper.

  • Mapping the nuclear environments of extreme coronal line emitting galaxies astro-ph.GA · 2026-06-02 · unverdicted · none · ref 100 · internal anchor

    Multi-epoch spectroscopy of 33 ECLEs shows coronal lines emitted at intermediate radii with log(distance)-log(black hole mass) slopes of 0.63 and 0.69 for [O III] and [Fe VII], consistent with photoionization setting the radii.