GPS/CSS radio sources and their relation to other AGN

Sadler, E. M.

doi:10.1002/asna.201512274

Cited by 38 publications

(37 citation statements)

References 43 publications

(58 reference statements)

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“…Its morphology is consistent with that of a small-scale edgebrightened FR II, and less consistent with a small-scale FR I, in which we would expect to detect a central core. This is consistent with predictions that the precursors of FR I galaxies are less luminous than 10 25 W Hz −1 (Tingay & Edwards 2015;Sadler 2016).…”

Section: Ci0008supporting

confidence: 92%

“…The ATLAS CSS sample is much fainter, reaching sub-mJy levels, with a mean of ∼1 mJy, but only contains flux density measurements at two frequencies. Sadler (2016) concluded that there is a large population of less-luminous GPS and CSS sources, which have so far eluded detailed study, due to the lack of sensitive large-area surveys at multiple frequencies, and the large time-requirement for characterising their morphologies with Very Long Baseline Interferometry (VLBI). Tingay & Edwards (2015) observed two such lowluminosity GPS and CSS sources with VLBI and proposed a luminosity-morphology break for compact radio galaxies analogous to the FR I/II break.…”

Section: Low-luminosity Gps and Css Sourcesmentioning

confidence: 99%

“…Examples of low-luminosity samples include Kunert-Bajraszewska et al (2010), Orienti & Dallacasa (2014), Sadler (2016), and Kunert-Bajraszewska (2016), which have typical luminosities of 10 25−26 , 10 25−30 , 10 22−26 , and 10 23−27 W Hz −1 , respectively at 1.4, 0.375, 20 and 1.4 GHz. Orienti & Dallacasa (2014) bring together eight samples from the literature that have estimated turnover frequencies and linear sizes, which we use as a comparison.…”

Section: Low-luminosity Gps and Css Sourcesmentioning

confidence: 99%

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High-resolution Observations of Low-luminosity Gigahertz-Peaked Spectrum and Compact Steep Spectrum Sources

Collier

Tingay

Callingham

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We present Very Long Baseline Interferometry observations of a faint and low-luminosity (L 1.4GHz < 10 27 W Hz −1 ) Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sample. We select eight sources from deep radio observations that have radio spectra characteristic of a GPS or CSS source and an angular size of θ 2 , and detect six of them with the Australian Long Baseline Array. We determine their linear sizes, and model their radio spectra using Synchrotron Self Absorption (SSA) and Free Free Absorption (FFA) models. We derive statistical model ages, based on a fitted scaling relation, and spectral ages, based on the radio spectrum, which are generally consistent with the hypothesis that GPS and CSS sources are young and evolving. We resolve the morphology of one CSS source with a radio luminosity of 10 25 W Hz −1 , and find what appear to be two hotspots spanning 1.7 kpc. We find that our sources follow the turnover-linear size relation, and that both homogenous SSA and an inhomogeneous FFA model can account for the spectra with observable turnovers. All but one of the FFA models do not require a spectral break to account for the radio spectrum, while all but one of the alternative SSA and power law models do require a spectral break to account for the radio spectrum. We conclude that our low-luminosity sample is similar to brighter samples in terms of their spectral shape, turnover frequencies, linear sizes, and ages, but cannot test for a difference in morphology.

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Section: Ci0008supporting

confidence: 92%

Section: Low-luminosity Gps and Css Sourcesmentioning

confidence: 99%

Section: Low-luminosity Gps and Css Sourcesmentioning

confidence: 99%

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High-resolution Observations of Low-luminosity Gigahertz-Peaked Spectrum and Compact Steep Spectrum Sources

Collier

Tingay

Callingham

et al. 2018

Monthly Notices of the Royal Astronomical Society

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“…For a group of radio AGN, the extent of their radio continuum emission can be related to the age of the nuclear activity. Compact steep spectrum sources (CSS) and gigahertz peaked sources (GPS) are the youngest family of radio AGN (O'Dea 1998;Murgia 2003;Fanti 2009;Sadler 2016;Orienti 2016), and in general, they can be considered younger radio AGN than extended sources. A fraction of the compact sources of our sample belong to this group of young radio AGN (see G14 and G15).…”

Section: Characterisation Of the Agn Samplementioning

confidence: 99%

Kinematics and physical conditions of H i in nearby radio sources

Maccagni

Morganti

Oosterloo

et al. 2017

A&A

222

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We present an analysis of the properties of neutral hydrogen (H i) in 248 nearby (0.02 < z < 0.25) radio galaxies with S 1.4 GHz > 30 mJy and for which optical spectroscopy is available. The observations were carried out with the Westerbork Synthesis Radio Telescope as the last large project before the upgrade of the telescope with phased array feed receivers (Apertif). The sample covers almost four orders of magnitude in radio power from log P 1.4 GHz = 22.5 W Hz −1 and 26.2 W Hz −1 . We detect H i in absorption in 27% ± 5.5% of the objects. The detections are found over the full range of radio power. However, the distribution and kinematics of the absorbing H i gas appear to depend on radio power, the properties of the radio continuum emission, and the dust content of the sources. Among the sources where H i is detected, gas with kinematics deviating from regular rotation is more likely found as the radio power increases. In the great majority of these cases, the H i profile is asymmetric with a significant blue-shifted component. This is particularly common for sources with log P 1.4 GHz > 24 W Hz −1 , where the radio emission is small, possibly because these radio sources are young. The same is found for sources that are bright in the mid-infrared, i.e. sources rich in heated dust. In these sources, the H i is outflowing likely under the effect of the interaction with the radio emission. Conversely, in dust-poor galaxies, and in sources with extended radio emission, at all radio powers we only detect H i distributed in a rotating disk. Stacking experiments show that in sources for which we do not detect H i in absorption directly, the H i has a column density that is lower than 3.5 × 10 17 (T spin /c f ) cm −2 . We use our results to predict the number and type of H i absorption lines that will be detected by the upcoming surveys of the Square Kilometre Array precursors and pathfinders (Apertif, MeerKAT, and ASKAP).

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“…Hence, WISE color diagnostics and photometry could, in general, be considered as a very useful tool when selecting candidates for Compton-thick AGN among compact radio galaxies. Note in this context that, compact radio sources are particularly abundant in flux-limited radio samples, constituting ∼ 10% of the bright radio-source population (O'Dea 1998;Sadler 2016).…”

Section: Discussionmentioning

confidence: 99%

Infrared Diagnostics of the ISM in the Circumnuclear Environments of the Youngest Radio Galaxies

2018

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We present a systematic analysis of the mid-infrared (MIR) properties of the youngest radio galaxies, based on low-resolution data provided by the WISE and IRAS satellites. We restrict our analysis to sources with available X-ray data that constitute the earliest phase of radio galaxy evolution, i.e. those classified as Gigahertz Peaked Spectrum (GPS) and/or Compact Symmetric Objects (CSOs). In our sample of 29 objects, we find that the host galaxies are predominantly red/yellow ellipticals, with some of them displaying distorted morphology. We find a variety of MIR colors, and observe that the sources in which the MIR emission is dominated by the ISM component uniformly populate the region occupied by galaxies with a wide range of pronounced (≥ 0.5M yr −1 ) star formation activity. We compare the MIR color distribution in our sample to that in the general population of local AGN, in the population of evolved FR II radio galaxies, and also in the population of radio galaxies with recurrent jet activity. We conclude that the triggering of radio jets in AGN does not differentiate between elliptical hosts with substantially different fractions of young stars; instead there is a relationship between the jet duty cycle and the ongoing star formation. The distribution of the sub-sample of our sources with z < 0.4 on the low-resolution MIR vs. absorption-corrected X-ray luminosity plane is consistent with the distribution of a sample of local AGN. Finally, we comment on the star formation rates of the two γ-ray detected sources in our sample, 1146+596 & 1718-649.

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GPS/CSS radio sources and their relation to other AGN

Cited by 38 publications

References 43 publications

High-resolution Observations of Low-luminosity Gigahertz-Peaked Spectrum and Compact Steep Spectrum Sources

High-resolution Observations of Low-luminosity Gigahertz-Peaked Spectrum and Compact Steep Spectrum Sources

Kinematics and physical conditions of H i in nearby radio sources

Infrared Diagnostics of the ISM in the Circumnuclear Environments of the Youngest Radio Galaxies

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