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.
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
21 June 2000
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), .
(doi:10.1046/j.1365-8711.2000.03430.x).
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