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Lookup NU author(s): Dr Ann Njeri, Dr Chris HarrisonORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2024 The Author(s).Deep radio surveys of e xtragalactic le gac y fields trace a large range of spatial and brightness temperature sensitivity scales, and therefore have differing biases to radio-emitting physical components within galaxies. This is particularly true of radio surveys performed at ≤ 1 arcsec angular resolutions, and so robust comparisons are necessary to better understand the biases present in each survey. We present a multiresolution and multiwav elength analysis of the sources detected in a new Very Long Baseline Array (VLBA) survey of the Cosmic Assembly Near-IR Deep Extrag alactic Leg acy Survey Great Observatories Origins Deep Surv e y-North field. F or the 24 VLBA-selected sources described in Paper I, we augment the VLBA data with EVN data, and ~0.1-1 arcsec angular resolution data provided by Very Large Array (VLA) and enhanced-Multi Element Remotely Linked Interferometry Network. This sample includes new active galactic nuclei (AGN) detected in this field, thanks to a new source extraction technique that adopts priors from ancillary multiwavelength data. The high brightness temperatures of these sources ( TB ≥ 106 K) confirm AGN cores, that would often be missed or ambiguous in lower-resolution radio data of the same sources. Furthermore, only 15 sources are identified as 'radiative' AGN based on available X-ray and infrared constraints. By combining VLA and VLBA measurements, we find evidence that the majority of the extended radio emission is also AGN dominated, with only three sources with evidence for extended potentially star formation-dominated radio emission. We demonstrate the importance of wide-field multiresolution (arcsecond-milliarcsecond) co v erage of the faint radio source population, for a complete picture of the multiscale processes within these galaxies.
Author(s): Njeri A, Deane RP, Radcliffe JF, Beswick RJ, Thomson AP, Muxlow TWB, Garrett MA, Harrison CM
Publication type: Article
Publication status: Published
Journal: Monthly Notices of the Royal Astronomical Society
Year: 2024
Volume: 528
Issue: 4
Pages: 6141-6158
Print publication date: 01/03/2024
Online publication date: 06/02/2024
Acceptance date: 02/02/2024
Date deposited: 15/08/2024
ISSN (print): 0035-8711
ISSN (electronic): 1365-2966
Publisher: Oxford University Press
URL: https://doi.org/10.1093/mnras/stae381
DOI: 10.1093/mnras/stae381
Data Access Statement: Data underlying this article are publicly available in the NRAO Archive Access Tool under VLBA project code BD176. The reduced data will be shared on reasonable request to the corresponding author.
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