New giant radio sources and underluminous radio halos in two galaxy clusters

¹ Dipartimento di Fisica e Astronomia, Università di Bologna, via P. Gobetti 93/2, 40129 Bologna, Italy
e-mail: vcuciti@ira.inaf.it
² INAF-Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
³ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
⁴ National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Post Bag 3, 411007 Pune, India

Received: 15 May 2017
Accepted: 16 September 2017

Abstract

Aims. The aim of this work is to analyse the radio properties of the massive and dynamically disturbed clusters Abell 1451 and Zwcl 0634.1+4750, especially focusing on the possible presence of diffuse emission.

Methods. We present new Giant Metrewave Radio Telescope (GMRT) 320 MHz and Jansky Very Large Array (JVLA) 1.5 GHz observations of these two clusters.

Results. We found that both Abell 1451 and Zwcl 0634.1+4750 host a radio halo with a typical spectrum (α ~ 1−1.3). Similarly to a few other cases reported in the recent literature, these radio halos are significantly fainter in radio luminosity with respect to the current radio power-mass correlations and they are smaller than classical giant radio halos. These underluminous sources might contribute to elucidating the complex mechanisms of formation and evolution of radio halos. Furthermore, we detected a candidate radio relic at large distance from the cluster centre in Abell 1451 and a peculiar head-tail (HT) radio galaxy in Zwcl 0634.1+4750, which might be interacting with a shock front.