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MINI REVIEW article

Front. Astron. Space Sci.
Sec. Extragalactic Astronomy
Volume 12 - 2025 | doi: 10.3389/fspas.2025.1548632
This article is part of the Research Topic Broad-Band Spectral Energy Distributions in AGNs - Advances and the Future View all 4 articles

The Coronal Line Region of Active Galactic Nuclei

Provisionally accepted
Alberto Rodriguez-Ardila Alberto Rodriguez-Ardila 1*Fernando Cerqueira-Campos Fernando Cerqueira-Campos 2
  • 1 Laboratório Nacional de Astrofí­sica, Itajubá, Brazil
  • 2 National Institute of Space Research (INPE), São José dos Campos, São Paulo, Brazil

The final, formatted version of the article will be published soon.

    Forbidden coronal lines has traditionally called the attention due to the high-energy photons required for their production (IP >100 eV, where IP is the ionisation potential of the transitions that originate the line). As such, they are regarded as the most highly ionised component of Active Galactic Nuclei (AGN). For decades, it was thought that they were only formed in the inner portions of the narrow line region (NLR). Nowadays, due to the larger sensitivity of the detectors and the availability of integral field unit (IFU) spectrographs, that emission in addition to the nuclear component is found to be extended up to a few kiloparsecs away from the active centre.In this review, we highlight the most important aspects of the coronal emission and discuss the recent developments in the field. In particular, we emphasize the discovery that they can be used to determine the mass of the central supermassive black hole, to reconstruct the SED, as well as to trace the most energetic feedback component of the ionised gas in AGN.

    Keywords: Active -galaxies, Line: Formation -, Galaxies - jets, Line - profiles, galaxies: Seyfert

    Received: 19 Dec 2024; Accepted: 03 Feb 2025.

    Copyright: © 2025 Rodriguez-Ardila and Cerqueira-Campos. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Alberto Rodriguez-Ardila, Laboratório Nacional de Astrofí­sica, Itajubá, Brazil

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