The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results

This is the first paper of a series exploring the multi-frequency properties of a sample of eleven nearby low excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars, warm and cold gas, radio jets) with the aim of improving ou...

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Main Authors: Ruffa, I, Prandoni, I, Laing, R, Paladino, R, Parma, P, de Ruiter, H, Mignano, A, Davis, T, Bureau, M, Warren, J
Format: Journal article
Published: Oxford University Press 2019
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author Ruffa, I
Prandoni, I
Laing, R
Paladino, R
Parma, P
de Ruiter, H
Mignano, A
Davis, T
Bureau, M
Warren, J
author_facet Ruffa, I
Prandoni, I
Laing, R
Paladino, R
Parma, P
de Ruiter, H
Mignano, A
Davis, T
Bureau, M
Warren, J
author_sort Ruffa, I
collection OXFORD
description This is the first paper of a series exploring the multi-frequency properties of a sample of eleven nearby low excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars, warm and cold gas, radio jets) with the aim of improving our understanding of the AGN fuelling/feedback cycle in LERGs. We present ALMA Band 6 12CO(2-1) and continuum observations of nine sources. Continuum emission from the radio cores was detected in all objects. Six sources also show mm emission from jets on kpc/sub-kpc scales. The jet structures are very similar at mm and cm wavelengths. We conclude that synchrotron emission associated with the radio jets dominates the continuum spectra up to 230 GHz. The 12CO(2-1) line was detected in emission in six out of nine objects, with molecular gas masses ranging from 2 × 107 to 2 × 1010 M⊙. The CO detections show disc-like structures on scales from ≈0.2 to ≈10 kpc. In one case (NGC 3100) the CO disc presents some asymmetries and is disrupted in the direction of the northern radio jet, indicating a possible jet/disc interaction. In IC 4296, CO is detected in absorption against the radio core as well as in emission. In four of the six galaxies with CO detections, the gas rotation axes are roughly parallel to the radio jets in projection; the remaining two cases show large misalignments. In those objects where optical imaging is available, dust and CO appear to be co-spatial.
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spelling oxford-uuid:2eee87b1-32a4-4f38-ac47-6ef9290731322022-03-26T12:52:04ZThe AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early resultsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2eee87b1-32a4-4f38-ac47-6ef929073132Symplectic Elements at OxfordOxford University Press2019Ruffa, IPrandoni, ILaing, RPaladino, RParma, Pde Ruiter, HMignano, ADavis, TBureau, MWarren, JThis is the first paper of a series exploring the multi-frequency properties of a sample of eleven nearby low excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars, warm and cold gas, radio jets) with the aim of improving our understanding of the AGN fuelling/feedback cycle in LERGs. We present ALMA Band 6 12CO(2-1) and continuum observations of nine sources. Continuum emission from the radio cores was detected in all objects. Six sources also show mm emission from jets on kpc/sub-kpc scales. The jet structures are very similar at mm and cm wavelengths. We conclude that synchrotron emission associated with the radio jets dominates the continuum spectra up to 230 GHz. The 12CO(2-1) line was detected in emission in six out of nine objects, with molecular gas masses ranging from 2 × 107 to 2 × 1010 M⊙. The CO detections show disc-like structures on scales from ≈0.2 to ≈10 kpc. In one case (NGC 3100) the CO disc presents some asymmetries and is disrupted in the direction of the northern radio jet, indicating a possible jet/disc interaction. In IC 4296, CO is detected in absorption against the radio core as well as in emission. In four of the six galaxies with CO detections, the gas rotation axes are roughly parallel to the radio jets in projection; the remaining two cases show large misalignments. In those objects where optical imaging is available, dust and CO appear to be co-spatial.
spellingShingle Ruffa, I
Prandoni, I
Laing, R
Paladino, R
Parma, P
de Ruiter, H
Mignano, A
Davis, T
Bureau, M
Warren, J
The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
title The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
title_full The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
title_fullStr The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
title_full_unstemmed The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
title_short The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
title_sort agn fuelling feedback cycle in nearby radio galaxies i alma observations and early results
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