Radio footprints of a minor merger in the Shapley Supercluster: from supercluster down to galactic scales

Autor: Venturi, T, Giacintucci, S, Merluzzi, P, Bardelli, S, Busarello, G, Dallacasa, D, Sikhosana, SP, Marvil, J, Smirnov, O, Bourdin, H, Mazzotta, P, Rossetti, M, Rudnick, L, Bernardi, G, Bruggen, M, Carretti, E, Cassano, R, Di Gennaro, G, Gastaldello, F, Kale, R, Knowles, K, Koribalski, BS, Heywood, I, Hopkins, AM, Norris, RP, Reiprich, TH, Tasse, C, Vernstrom, T, Zucca, E, Bester, LH, Diego, JM, Kanapathippillai, J
Přispěvatelé: Ministero degli Affari Esteri e della Cooperazione Internazionale, Department of Atomic Energy (India), South African Radio Astronomy Observatory, National Research Foundation (South Africa)
Jazyk: angličtina
Rok vydání: 2022
Předmět:
clusters: individual: A3558 [Galaxies]
Galaxies - clusters - individual - A3558
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Settore FIS/05
Astrophysics::High Energy Astrophysical Phenomena
Galaxies - clusters - individual - SC 1329-313
Astrophysics - cosmology and nongalactic astrophysics
Astrophysics - astrophysics of galaxies
Galaxies - clusters - individual - SC 1327-312
FOS: Physical sciences
Astronomy and Astrophysics
Galaxies - clusters - individual - A3562
Astrophysics::Cosmology and Extragalactic Astrophysics
clusters: general [Galaxies]
Galaxies - clusters - general
Radio continuum - galaxies
clusters: individual: A3562 [Galaxies]
Galaxies: clusters: individual: A3558
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
Galaxies: clusters: individual: SC 1329–313
clusters: individual: SC 1329–313 [Galaxies]
Galaxies: clusters: general
Galaxies: clusters: individual: A3562
Astrophysics::Galaxy Astrophysics
Zdroj: Astronomy & Astrophysics, 660:A81
Digital.CSIC. Repositorio Institucional del CSIC
instname
Popis: et al.
[Context] The Shapley Supercluster (⟨z⟩≈0.048) contains several tens of gravitationally bound clusters and groups, making it an ideal subject for radio studies of cluster mergers.
[Aims] We used new high sensitivity radio observations to investigate the less energetic events of mass assembly in the Shapley Supercluster from supercluster down to galactic scales.
[Methods] We created total intensity images of the full region between A3558 and A3562, from ∼230 to ∼1650 MHz, using ASKAP, MeerKAT and the GMRT, with sensitivities ranging from ∼6 to ∼100 μJy beam−1. We performed a detailed morphological and spectral study of the extended emission features, complemented with ESO-VST optical imaging and X-ray data from XMM-Newton.
[Results] We report the first GHz frequency detection of extremely low brightness intercluster diffuse emission on a ∼1 Mpc scale connecting a cluster and a group, namely: A3562 and the group SC 1329–313. It is morphologically similar to the X-ray emission in the region. We also found (1) a radio tail generated by ram pressure stripping in the galaxy SOS 61086 in SC 1329–313; (2) a head-tail radio galaxy, whose tail is broken and culminates in a misaligned bar; (3) ultrasteep diffuse emission at the centre of A3558. Finally (4), we confirm the ultra-steep spectrum nature of the radio halo in A3562.
[Conclusions] Our study strongly supports the scenario of a flyby of SC 1329–313 north of A3562 into the supercluster core. This event perturbed the centre of A3562, leaving traces of this interaction in the form of turbulence between A3562 and SC 1329–313, at the origin of the radio bridge and eventually affecting the evolution of individual supercluster galaxies by triggering ram pressure stripping. Our work shows that minor mergers can be spectacular and have the potential to generate diffuse radio emission that carries important information on the formation of large-scale structures in the Universe.
T. Venturi and G. Bernardi acknowledge the support from the Ministero degli Affari Esteri e della Cooperazione Internazionale, Direzione Generale per la Promozione del Sistema Paese, Progetto di Grande Rilevanza ZA18GR02. R. Kale acknowledges the support of the Department of Atomic Energy, Government of India under project no. 12-R&D-TFR-5.02-0700. S. P. Sikhosana acknowledges funding support from the South African Radio Astronomy Observatory (SARAO) and the National Research Foundation (NRF). O. Smirnov’s research is supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation.
Databáze: OpenAIRE
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