English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

[Abridged] Physical and evolutionary properties of the sub-mJy radiopopulation are not entirely known. The radio/optical analysis of the ATESP 5GHz sample has revealed a significant class of compact flat/invertedradio-spectrum sources associated to early-type galaxies up to redshift 2. Suchsources are most plausibly triggered by an AGN, but their observationalproperties are not entirely consistent with those of standard radio galaxypopulations. In the present work we aim at a better understanding of the radiospectra of such sources and ultimately of the nature of AGNs at sub-mJy fluxlevels. We used the ATCA to get multi-frequency (4.8, 8.6 and 19 GHz)quasi-simultaneous observations for a representative sub-sample of ATESP radiosources associated with early-type galaxies (26 objects with S>0.6 mJy). Thiscan give us insight into the accretion/radiative mechanism that is at work,since different regimes display different spectral signatures in the radiodomain. From the analysis of the radio spectra, we find that our sources aremost probably jet-dominated systems. ADAF models are ruled out by the highfrequency data, while ADAF+jet scenarios are still consistent withflat/moderately inverted-spectrum sources, but are not required to explain thedata. We compared our sample with high (>20 GHz) frequency selected surveys,finding spectral properties very similar to the ones of much brighter (S>500mJy) radio galaxies extracted from the Massardi et al. (2008) sample. Linearsizes of ATESP 5 GHz sources associated with early type galaxies are also oftenconsistent with the ones of brighter B2 and 3C radio galaxies, with possibly avery compact component that could be associated at least in part to (obscured)radio-quiet quasar-like objects and/or low power BL Lacs.

The ATESP 5 GHz radio survey. III. 4.8, 8.6 and 19 GHz follow-up observations of radio galaxies