A morphological comparison between giant radio halos and radio mini--halos in galaxy clusters

Abstract

In this letter we present a morphological comparison between giant radio halos and radio mini-halos in galaxy clusters based on radio--X-ray luminosity, P_{1.4}-L_X, and radio luminosity-size, P_{1.4}-R_H, correlations. We report evidence that P_{1.4}-L_X and P_{1.4}-R_H trends may also exist for mini--halos: mini--halo clusters share the same region of giant halo clusters in the (P_{1.4},L_X) plane, whereas they are clearly separated in the (P_{1.4},R_H) plane. The synchrotron emissivity of mini-halos is found to be more than 50 times larger than that of giant halos, implying a very efficient process for their origins. By assuming a scenario of sporadical turbulent particle re-acceleration for both giant and mini halos, we discuss basic physical differences between these sources. Regardless of the origin of the turbulence, a more efficient source of injection of particles, which eventually takes part in the re-acceleration process, is required in mini-halos, and this may result from the central radio galaxy or from proton-proton collisions in the dense cool core regions.

4 pages, 3 figures, A&A Letter in press

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Cited by in corpus (10)

• Diffuse Radio Emission from Galaxy Clusters
• Mapping the particle acceleration in the cool core of the galaxy cluster RX J1720.1+2638
• Radio and X-ray connection in radio mini-halos: implications for hadronic models
• On the relation between mini-halos and AGN feedback in clusters of galaxies
• Testing Secondary Models for the Origin of Radio Mini-Halos in Galaxy Clusters
• A distant radio mini-halo in the Phoenix galaxy cluster
• Early Science with the Karoo Array Telescope: a Mini-Halo Candidate in Galaxy Cluster Abell 3667
• A Chandra study of Abell 795 -- a sloshing cluster with a FR0 radio galaxy at its center
• The correlation between radio power and Mach number for radio relics in galaxy clusters
• Discovery of large-scale radio emission enveloping the mini-halo in the most X-ray luminous galaxy cluster RX~J1347.5-1145