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Radio Galaxy Zoo: the distortion of radio galaxies by galaxy clusters


Garon, AF and Rudnick, L and Wong, OI and Jones, TW and Kim, J-A and Andernach, H and Shabala, SS and Kapinska, D and Norris, RP and de Gasperin, F and Tate, J and Tang, H, Radio Galaxy Zoo: the distortion of radio galaxies by galaxy clusters, Astronomical Journal, 157, (3) Article 126. ISSN 0004-6256 (2019) [Refereed Article]

DOI: doi:10.3847/1538-3881/aaff62


We study the impact of cluster environment on the morphology of a sample of 4304 extended radio galaxies from Radio Galaxy Zoo. 87% of the sample lies within a projected 15 Mpc of an optically identified cluster. Brightest cluster galaxies (BCGs) are more likely to be radio sources than other cluster members are, and are also moderately bent. The surface density as a function of separation from cluster center of non-BCG radio galaxies follows a power law with index -1.100.03 out to 10 𝑟500 (∼7 Mpc), which is steeper than the corresponding distribution for optically-selected galaxies. Non-BCG radio galaxies are statistically more bent the closer they are to the cluster center. Within the inner 1.5 𝑟500(∼1 Mpc) of a cluster, non-BCG radio galaxies are statistically more bent in high mass clusters than in low mass clusters. Together, we find that non-BCG sources are statistically more bent in environments that exert greater ram pressure. We use the orientation of bent radio galaxies as an indicator of galaxy orbits, and find that they are preferentially in radial orbits. Away from clusters, there is a large population of bent radio galaxies, limiting their use as cluster locators; however, they are still located within statistically overdense regions. We investigate the asymmetry in the tail length of sources that have their tails aligned along the radius vector from the cluster center, and find that the length of the inward-pointing tail is weakly suppressed for sources close to the center of the cluster.

Item Details

Item Type:Refereed Article
Keywords:galaxies: clusters: intracluster medium - radio continuum: galaxies
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:130386
Year Published:2019
Funding Support:Australian Research Council (DE130101399)
Web of Science® Times Cited:14
Deposited By:Mathematics and Physics
Deposited On:2019-01-23
Last Modified:2020-05-20

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