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Radio Galaxy Zoo: a search for hybrid morphology radio galaxies


Kapinska, AD and Terentev, I and Wong, OI and Shabala, SS and Andernach, H and Rudnick, L and Storer, L and Banfield, JK and Willett, KW and de Gasparin, F and Lintott, CJ and Lopez-Sanchez, AR and Middelberg, E and Norris, RP and Shawinski, S and Seymour, N and Simmons, B, Radio Galaxy Zoo: a search for hybrid morphology radio galaxies, Astronomical Journal, 154, (6) Article 253. ISSN 0004-6256 (2017) [Refereed Article]


Copyright Statement

Copyright 2017 The American Astronomical Society. Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0)

DOI: doi:10.3847/1538-3881/aa90b7


Hybrid morphology radio sources (HyMoRS) are a rare type of radio galaxy that display different Fanaroff–Riley classes on opposite sides of their nuclei. To enhance the statistical analysis of HyMoRS, we embarked on a large-scale search of these sources within the international citizen science project, Radio Galaxy Zoo (RGZ). Here, we present 25 new candidate hybrid morphology radio galaxies. Our selected candidates are moderate power radio galaxies (Lmedian = 4.7 x 1024 w Hz-1 sr-1) at redshifts 0.14 < z < 1.0. Hosts of nine candidates have spectroscopic observations, of which six are classified as quasars, one as high- and two as low-excitation galaxies. Two candidate HyMoRS are giant (>1 Mpc) radio galaxies, one resides at the center of a galaxy cluster, and one is hosted by a rare green bean galaxy. Although the origin of the hybrid morphology radio galaxies is still unclear, this type of radio source starts depicting itself as a rather diverse class. We discuss hybrid radio morphology formation in terms of the radio source environment (nurture) and intrinsically occurring phenomena (nature; activity cessation and amplification), showing that these peculiar radio galaxies can be formed by both mechanisms. While high angular resolution follow-up observations are still necessary to confirm our candidates, we demonstrate the efficacy of the RGZ in the pre-selection of these sources from all-sky radio surveys, and report the reliability of citizen scientists in identifying and classifying complex radio sources.

Item Details

Item Type:Refereed Article
Keywords:galaxies, jets, quasars, supermassive black holes, radio continuum, lines and bands, clusters
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Cosmology and extragalactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Shabala, SS (Associate Professor Stas Shabala)
ID Code:123650
Year Published:2017
Funding Support:Australian Research Council (DE130101399)
Web of Science® Times Cited:29
Deposited By:Mathematics and Physics
Deposited On:2018-01-16
Last Modified:2018-04-30
Downloads:132 View Download Statistics

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