2008/06/11 by R. Cassano, Myriam Gitti, M. Gitti +1
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Luminosity #Physics #Radio Astronomy Observations and Technology #Radio halo #astro-ph
paper · pdf · doi:10.1051/0004-6361:200810179
4 pages, 3 figures, A&A Letter in press
arxiv created 2008/06/11 · openalex publication_date 2008/06/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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, P1.4-LX, and radio luminosity-size, P1.4-RH, correlations. We report evidence that P1.4-LX and P1.4-RH trends may also exist for mini-halos: mini-halo clusters share the same region of giant halo clusters in the plane, whereas they are clearly separated in the 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.