<i>WISE</i> mid-infrared properties of compact active galactic nuclei selected from the high radio frequency AT20G survey

Chhetri, Rajan; Kimball, Amy; Ekers, R. D.; Mahony, E. K.; Sadler, E. M.; Jarrett, T. H.

doi:10.1093/mnras/staa513

Cited by 6 publications

(6 citation statements)

References 45 publications

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“…Very few FRI/II and GPS/CSS sources have WISE colors as red as our sample. A similar result was seen by Chhetri et al (2020), who found that compact radio AGN have bluer WISE colors than AGN selected by optical/IR techniques. Thus, although our sample was pre-selected to have very red WISE colors, other classes of object with similarly compact radio sources (CCS/GPS/HFP) do not share these MIR colors.…”

Section: Wise Colors Of Compact Radio Agnsupporting

confidence: 84%

Radio Spectra of Luminous, Heavily Obscured WISE-NVSS Selected Quasars

Patil,

Whittle,

Nyland

et al. 2022

Preprint

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We present radio spectra spanning 0.1 − 10 GHz for the sample of heavily obscured luminous quasars with extremely red mid-infrared-optical colors and compact radio emission. The spectra are constructed from targeted 10 GHz observations and archival radio survey data, which together yield 6 − 11 flux density measurements for each object. Our suite of Python tools for modeling the radio spectra is publicly available on Github. Our primary result is that most (61%) of the sample have peaked or curved radio spectra and many (36%) could be classified as Gigahertz Peaked Spectrum (GPS) sources. This indicates compact emission regions likely arising from recently triggered radio jets. Assuming synchrotron self-absorption (SSA) generates the peaks, we infer compact source sizes (3 − 100 pc) with strong magnetic fields (6 − 100 mG) and young ages (30 − 10 4 years). Conversely, free-free absorption (FFA) could also create peaks due to the high column densities associated with the deeply embedded nature of the sample. However, we find no correlations between the existence or frequency of the peaks and any parameters of the MIR emission. The high-frequency spectral indices are steep (α ≈ −1) and correlate, weakly, with the ratio of MIR photon energy density to magnetic energy density, suggesting that the spectral steepening could arise from inverse Compton scattering off the intense MIR photon field. This study provides a foundation for combining multi-frequency and mixed-resolution radio survey data for understanding the impact of young radio jets on the ISM and star formation rates of their host galaxies.

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Section: Wise Colors Of Compact Radio Agnsupporting

confidence: 84%

Radio Spectra of Luminous, Heavily Obscured WISE-NVSS Selected Quasars

Patil,

Whittle,

Nyland

et al. 2022

Preprint

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“…Mid-infrared colour-colour plots are commonly used as a diagnostic tool for radiatively efficient AGN activity and sample selections (see e.g. Donley et al 2012 ;Mateos et al 2012 ;Stern et al 2012 ;Assef et al 2013 ;Secrest et al 2015 ;Chhetri et al 2020 ), though their usefulness for selecting AGN is limited to very bright radiatively efficient sources (quasars and bright Seyfert galaxies), where the torus component dominates, and often fainter AGN are missed (see e.g. G ürkan, Hardcastle & Jarvis 2014 ;Rovilos et al 2014 ;Mingo et al 2016 ;G ürkan et al 2018Retana-Montenegro & R öttgering 2020 ).…”

Section: Mid-ir Diagnosticsmentioning

confidence: 99%

“…Many of these radio sources seem to be young or unlikely to grow to large sizes, so it is yet unclear how they tie in with the evolved FRI/II classes, and what impact they might have beyond their host galaxies (e.g. Chhetri et al 2020 ;Patil et al 2020 ). We are also achieving greater insight on the bright compact steep spectrum and gigahertz peaked spectrum populations, with radio powers comparable to those of extended radio galaxies, but which are far too numerous to always evolve into FRIs and FRIIs (see e.g.…”

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confidence: 99%

Accretion mode versus radio morphology in the LOFAR Deep Fields

Mingo

Croston

Best

et al. 2022

Monthly Notices of the Royal Astronomical Society

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Radio-loud active galaxies have two accretion modes [radiatively inefficient (RI) and radiatively efficient (RE)], with distinct optical and infrared signatures, and two jet dynamical behaviours, which in arcsec- to arcmin-resolution radio surveys manifest primarily as centre- or edge-brightened structures [Fanaroff-Riley (FR) class I and II]. The nature of the relationship between accretion mode and radio morphology (FR class) has been the subject of long debate. We present a comprehensive investigation of this relationship for a sample of 286 well-resolved radio galaxies in the LOFAR Two-metre Sky Survey Deep Fields (LoTSS-Deep) first data release, for which robust morphological and accretion mode classifications have been made. We find that two-thirds of luminous FRII radio galaxies are RI, and identify no significant differences in the visual appearance or source dynamic range (peak/mean surface brightness) of the RI and RE FRIIs, demonstrating that both RI and RE systems can produce FRII structures. We also find a significant population of low-luminosity FRIIs (predominantly RI), supporting our earlier conclusion that FRII radio structures can be produced at all radio luminosities. We demonstrate that in the luminosity range where both morphologies are present, the probability of producing FRI or FRII radio morphology is directly linked to stellar mass, while across all morphologies and luminosities, RE accretion occurs in systems with high specific star formation rate, presumably because this traces fuel availability. In summary, the relationship between accretion mode and radio morphology is very indirect, with host-galaxy environment controlling these two key parameters in different ways.

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“…Mid-infrared colour-colour plots are commonly used as a diagnostic tool for radiatively efficient AGN activity and sample selections (see e.g. Mateos et al 2012;Stern et al 2012;Donley et al 2012;Assef et al 2013;Secrest et al 2015;Chhetri et al 2020), though their usefulness for selecting AGN is limited to very bright radiatively efficient sources (quasars and bright Seyfert galaxies), where the torus component dominates, and often fainter AGN are missed (see e.g. Rovilos et al 2014;Gürkan et al 2014Gürkan et al , 2018Gürkan et al , 2019Mingo et al 2016;Retana-Montenegro & Röttgering 2020).…”

Section: Mid-ir Diagnosticsmentioning

confidence: 99%

“…Many of these radio sources seem to be young or unlikely to grow to large sizes, so it is yet unclear how they tie in with the evolved FRI/II classes, and what impact they might have beyond their host galaxies (e.g. Chhetri et al 2020;Patil et al 2020). We are also achieving greater insight on the bright compact steep spectrum (CSS) and gigahertz peaked spectrum (GPS) populations, with radio powers comparable to those of extended radio galaxies, but which are far too numerous to always evolve into FRIs and FRIIs (see e.g.…”

Section: Introductionmentioning

confidence: 99%

Accretion mode versus radio morphology in the LOFAR Deep Fields

Mingo,

Croston,

Best

et al. 2022

Preprint

View full text Add to dashboard Cite

Radio-loud active galaxies have two accretion modes [radiatively inefficient (RI) and radiatively efficient (RE)], with distinct optical and infrared signatures, and two jet dynamical behaviours, which in arcsec-to arcmin-resolution radio surveys manifest primarily as centre-or edge-brightened structures [Fanaroff-Riley (FR) class I and II]. The nature of the relationship between accretion mode and radio morphology (FR class) has been the subject of long debate. We present a comprehensive investigation of this relationship for a sample of 286 well-resolved radio galaxies in the LOFAR Two-metre Sky Survey Deep Fields (LoTSS-Deep) first data release, for which robust morphological and accretion mode classifications have been made. We find that two-thirds of luminous FRII radio galaxies are RI, and identify no significant differences in the visual appearance or source dynamic range (peak/mean surface brightness) of the RI and RE FRIIs, demonstrating that both RI and RE systems can produce FRII structures. We also find a significant population of low-luminosity FRIIs (predominantly RI), supporting our earlier conclusion that FRII radio structures can be produced at all radio luminosities. We demonstrate that in the luminosity range where both morphologies are present, the probability of producing FRI or FRII radio morphology is directly linked to stellar mass, while across all morphologies and luminosities, RE accretion occurs in systems with high specific star formation rate, presumably because this traces fuel availability. In summary, the relationship between accretion mode and radio morphology is very indirect, with host-galaxy environment controlling these two key parameters in different ways.

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WISE mid-infrared properties of compact active galactic nuclei selected from the high radio frequency AT20G survey

Cited by 6 publications

References 45 publications

Radio Spectra of Luminous, Heavily Obscured WISE-NVSS Selected Quasars

Radio Spectra of Luminous, Heavily Obscured WISE-NVSS Selected Quasars

Accretion mode versus radio morphology in the LOFAR Deep Fields

Accretion mode versus radio morphology in the LOFAR Deep Fields

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