0004-637X_722_2_1333.pdf (322.05 kB)
THE ORIGIN OF THE INFRARED EMISSION IN RADIO GALAXIES. III. ANALYSIS OF 3CRR OBJECTS
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posted on 2023-06-08, 06:39 authored by D Dicken, C Tadhunter, David Axon, A Robinson, R Morganti, P KharbWe present Spitzer photometric data for a complete sample of 19 low-redshift (z < 0.1) 3CRR radio galaxies as part of our efforts to understand the origin of the prodigious mid-to far-infrared (MFIR) emission from radio-loud active galactic nuclei (AGNs). Our results show a correlation between AGN power (indicated by [O III]lambda 5007 emission line luminosity) and 24 mu m luminosity. This result is consistent with the 24 mu m thermal emission originating from warm dust heated directly by AGN illumination. Applying the same correlation test for 70 mu m luminosity against [O III] luminosity we find this relation to suffer from increased scatter compared to that of 24 mu m. In line with our results for the higher-radio-frequency-selected 2 Jy sample, we are able to show that much of this increased scatter is due to heating by starbursts that boost the far-infrared emission at 70 mu m in a minority of objects (17%-35%). Overall this study supports previous work indicating AGN illumination as the dominant heating mechanism for MFIR emitting dust in the majority of low-to-intermediate redshift radio galaxies (0.03 < z < 0.7), with the advantage of strong statistical evidence. However, we find evidence that the low-redshift broad-line objects (z < 0.1) are distinct in terms of their positions on the MFIR versus [O III] correlations.
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Astrophysical JournalISSN
0004-637XPublisher
Institute of PhysicsExternal DOI
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2Volume
722Page range
1333-1341Department affiliated with
- Physics and Astronomy Publications
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2012-02-06First Open Access (FOA) Date
2016-03-22First Compliant Deposit (FCD) Date
2017-03-07Usage metrics
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