Please use this identifier to cite or link to this item:
http://hdl.handle.net/2289/4375
Title: | ATLBS extended source sample : The evolution in radio source morphology with flux density |
Authors: | Saripalli, Lakshmi Subrahmanyan, Ravi Thorat, K. Ekers, R.D. Hunstead, R.W. Johnston, H.M. Sadler, E.M. |
Keywords: | Galaxies: active Radio continuum |
Issue Date: | 15-Mar-2012 |
Publisher: | IOP Publishing for the American Astronomical Society |
Citation: | Astrophysical Journal Supplement Series, 2012, Vol. 199, p27 |
Abstract: | Based on the Australia Telescope Low Brightness Survey (ATLBS) we present a sample of extended radio sources and derive morphological properties of faint radio sources. One hundred nineteen radio galaxies form the ATLBS Extended Source Sample (ATLBS-ESS) consisting of all sources exceeding 30 in extent and integrated flux densities exceeding 1 mJy. We give structural details along with information on galaxy identifications and source classifications. The ATLBS-ESS, unlike samples with higher flux-density limits, has almost equal fractions of FR-I and FR-II radio galaxies, with a large fraction of the FR-I population exhibiting 3C31-type structures. Significant asymmetry in lobe extents appears to be a common occurrence in the ATLBS-ESS FR-I sources compared with FR-II sources. We present a sample of 22 FR-Is at z > 0.5 with good structural information. The detection of several giant radio sources, with size exceeding 0.7 Mpc, at z > 1 suggests that giant radio sources are not less common at high redshifts. The ESS also includes a sample of 28 restarted radio galaxies. The relative abundance of dying and restarting sources is indicative of a model where radio sources undergo episodic activity in which an active phase is followed by a brief dying phase that terminates with restarting of the central activity; in any massive elliptical a few such activity cycles wherein adjacent events blend may constitute the lifetime of a radio source and such bursts of blended activity cycles may be repeated over the age of the host. The ATLBS-ESS includes a 2 Mpc giant radio galaxy with the lowest surface brightness lobes known to date. |
Description: | Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations) |
URI: | http://hdl.handle.net/2289/4375 |
ISSN: | 1538-4365-(online) 0067-0049 (Print) |
Alternative Location: | http://adsabs.harvard.edu/abs/2012ApJS..199...27S http://arxiv.org/abs/0911.4571 http://dx.doi.org/10.1088/0067-0049/199/2/27 |
Copyright: | 2012 The American Astronomical Society |
Appears in Collections: | Research Papers (A&A) |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
2012_AJS_199_27.pdf Restricted Access | Restricted Access. | 1.5 MB | Adobe PDF | View/Open Request a copy |
Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.