BASS. XLI. The Correlation between Mid-infrared Emission Lines and Active Galactic Nuclei Emission
Abstract We analyze Spitzer spectra of 140 active galactic nuclei (AGN) detected in the hard X-rays (14–195 keV) by the Burst Alert Telescope on board Swift. This sample allows us to probe several orders of magnitude in black hole masses (10 6 –10 9 M ⊙ ), Eddington ratios (10 −3 –1), X-ray luminosities (10 42 –10 45 erg s −1 ), and X-ray column densities (10 20 –10 24 cm −2 ). The AGN emission is expected to be the dominant source of ionizing photons with energies ≳50 eV, and therefore, high-ionization mid-infrared (MIR) emission lines such as [Ne v ] 14.32, 24.32 μ m and [O iv ] 25.89 μ m are predicted to be good proxies of AGN activity, and robust against obscuration effects. We find high detection rates (≳85%–90%) for the MIR coronal emission lines in our AGN sample. The luminosities of these lines are correlated with the 14–150 keV luminosity (with a typical scatter of σ ∼0.4–0.5 dex), strongly indicating that the MIR coronal line (CL) emission is driven by AGN activity. CLs are also tightly correlated to the bolometric luminosity ( σ ∼0.2–0.3 dex), calculated from careful analysis of the spectral energy distribution. We find that the relationship between the CL strengths and L 14–150 keV is independent of black hole mass, AGN luminosity, and Eddington ratio, and mostly not affected by high X-ray column densities. This confirms that the MIR CLs can be used as unbiased tracers of the AGN power for X-ray luminosities in the 10 42 –10 45 erg s −1 range.
Authors
- Darshan Kakkad (ORCID: https://orcid.org/0000-0002-2603-2639)
- Kyuseok Oh (ORCID: https://orcid.org/0000-0002-5037-951X)
- T. Kawamuro (ORCID: https://orcid.org/0000-0002-6808-2052)
- A. Tortosa (ORCID: https://orcid.org/0000-0003-3450-6483)
- Cláudio Ricci (ORCID: https://orcid.org/0000-0001-5231-2645)
- Michael Koss (ORCID: https://orcid.org/0000-0002-7998-9581)
- F. E. Bauer (ORCID: https://orcid.org/0000-0002-8686-8737)
- Daniel Stern (ORCID: https://orcid.org/0000-0003-2686-9241)
- Chin-Shin Chang (ORCID: https://orcid.org/0000-0001-9910-3234)
- M. Bierschenk
- Matthew J. Temple (ORCID: https://orcid.org/0000-0001-8433-550X)
- K. K. Gupta (ORCID: https://orcid.org/0009-0007-9018-1077)
- Jenna M. Cann (ORCID: https://orcid.org/0000-0003-1051-6564)
- Benny Trakhtenbrot (ORCID: https://orcid.org/0000-0002-3683-7297)
- Y. Díaz (ORCID: https://orcid.org/0000-0002-8604-1158)
- Rogério Riffel (ORCID: https://orcid.org/0000-0002-1321-1320)
- Kohei Ichikawa (ORCID: https://orcid.org/0000-0002-4377-903X)
- R. F. Mushotzky (ORCID: https://orcid.org/0000-0002-7962-5446)
- A. F. Rojas (ORCID: https://orcid.org/0000-0003-0006-8681)
- C. M. Urry (ORCID: https://orcid.org/0000-0002-0745-9792)
- Yanxia Xie (ORCID: https://orcid.org/0000-0002-9707-1037)
- Meredith C. Powell (ORCID: https://orcid.org/0000-0003-2284-8603)
- F. Ricci (ORCID: https://orcid.org/0000-0001-5742-5980)
- Fiona Harrison (ORCID: https://orcid.org/0000-0002-4226-8959)
- Shobita Satyapal (ORCID: https://orcid.org/0000-0003-2277-2354)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-11-27
- DOI
- https://doi.org/10.3847/1538-4357/ad844a
- Citations
- 6
- Primary Topic
- Gamma-ray bursts and supernovae
- Type
- article
- Field-Weighted Citation Impact
- 1.99
Funders
- Fondo Nacional de Desarrollo Científico y Tecnológico