The University of Southampton
University of Southampton Institutional Repository

Radio galaxies with a 'double-double morphology' - I. Analysis of the radio properties and evidence for interrupted activity in active galactic nuclei

Radio galaxies with a 'double-double morphology' - I. Analysis of the radio properties and evidence for interrupted activity in active galactic nuclei
Radio galaxies with a 'double-double morphology' - I. Analysis of the radio properties and evidence for interrupted activity in active galactic nuclei
We present four Mpc-sized radio galaxies which consist of a pair of double-lobed radio sources, aligned along the same axis, and with a coinciding radio core. We call these peculiar radio sources 'double-double' radio galaxies (DDRGs) and propose a general definition of such sources: a 'double-double' radio galaxy consists of a pair of double radio sources with a common centre. Furthermore, the two lobes of the inner radio source must have a clearly extended, edge-brightened radio morphology. Adopting this definition, we find several other candidate DDRGs in the literature. We find that in all sources the smaller (inner) pair of radio lobes is less luminous than the larger (outer) pair, and that the ratio of 1.4-GHz flux density of these two pairs appears to be anticorrelated with the projected linear size of the inner source. Also, the outer radio structures are large, exceeding 700kpc. We discuss possible formation scenarios of the DDRGs, and we conclude that an interruption of the jet-forming central activity is the most likely mechanism. For one of our sources (B1834+620) we have been able observationally to constrain the length of time of the interruption to a few Myr. We discuss several scenarios for the cause of the interruption, and suggest multiple encounters between interacting galaxies as a possibility. Finally, we discuss whether such interruptions help the formation of extremely large radio sources.
1365-2966
371-380
Schoenmakers, Arno P.
bd883879-6186-4cda-825a-30898673e7d5
de Bruyn, A.G.
07f202d5-5038-4790-b817-4ac8b0cc4c06
Röttgering, H.J.A.
071a6f5d-9a84-41f9-8ede-ba2764d76a19
- van der Laan, H.
83f62a46-62f6-4a34-9c2e-76e97b96262b
Kaiser, C.R.
a486973d-799c-401e-aa99-47dddd3972f7
Schoenmakers, Arno P.
bd883879-6186-4cda-825a-30898673e7d5
de Bruyn, A.G.
07f202d5-5038-4790-b817-4ac8b0cc4c06
Röttgering, H.J.A.
071a6f5d-9a84-41f9-8ede-ba2764d76a19
- van der Laan, H.
83f62a46-62f6-4a34-9c2e-76e97b96262b
Kaiser, C.R.
a486973d-799c-401e-aa99-47dddd3972f7

Schoenmakers, Arno P., de Bruyn, A.G., Röttgering, H.J.A., - van der Laan, H. and Kaiser, C.R. (2000) Radio galaxies with a 'double-double morphology' - I. Analysis of the radio properties and evidence for interrupted activity in active galactic nuclei. Monthly Notices of the Royal Astronomical Society, 315 (2), 371-380. (doi:10.1046/j.1365-8711.2000.03430.x).

Record type: Article

Abstract

We present four Mpc-sized radio galaxies which consist of a pair of double-lobed radio sources, aligned along the same axis, and with a coinciding radio core. We call these peculiar radio sources 'double-double' radio galaxies (DDRGs) and propose a general definition of such sources: a 'double-double' radio galaxy consists of a pair of double radio sources with a common centre. Furthermore, the two lobes of the inner radio source must have a clearly extended, edge-brightened radio morphology. Adopting this definition, we find several other candidate DDRGs in the literature. We find that in all sources the smaller (inner) pair of radio lobes is less luminous than the larger (outer) pair, and that the ratio of 1.4-GHz flux density of these two pairs appears to be anticorrelated with the projected linear size of the inner source. Also, the outer radio structures are large, exceeding 700kpc. We discuss possible formation scenarios of the DDRGs, and we conclude that an interruption of the jet-forming central activity is the most likely mechanism. For one of our sources (B1834+620) we have been able observationally to constrain the length of time of the interruption to a few Myr. We discuss several scenarios for the cause of the interruption, and suggest multiple encounters between interacting galaxies as a possibility. Finally, we discuss whether such interruptions help the formation of extremely large radio sources.

This record has no associated files available for download.

More information

Published date: 21 June 2000

Identifiers

Local EPrints ID: 14770
URI: http://eprints.soton.ac.uk/id/eprint/14770
ISSN: 1365-2966
PURE UUID: bc8fee91-28de-4adf-afef-2735001e760d

Catalogue record

Date deposited: 28 Feb 2005
Last modified: 15 Mar 2024 05:31

Export record

Altmetrics

Contributors

Author: Arno P. Schoenmakers
Author: A.G. de Bruyn
Author: H.J.A. Röttgering
Author: H. - van der Laan
Author: C.R. Kaiser

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×