Role of intracluster supernovae in radio mini-haloes in galaxy clusters

Abstract

Abstract A possibility of generating a population of cosmic ray particles accelerated in supernovae type Ia (SNIa) remnants in the intracluster medium (ICM) is discussed. The presently constrained host-less SNIa rates in the clusters are found to be sufficient to fill a few hundred kpc region with cosmic ray electrons within their typical synchrotron lifetime of 100 Myr. The SNIa have already been considered potential sources of excess Fe abundance in cool-core clusters, distributed heating and turbulence in ICM. A good fraction of total radio power from mini-haloes can be sourced from the SNIa energy deposited in the ICM with required energy conversion efficiency ≤1 per cent. The radio power estimated from low Mach-number shock acceleration in SNIa remnants is consistent with the observations within the uncertainties in the estimates. Some observational properties of the radio mini-haloes are broadly consistent with the SNIa scenario. It is also speculated that radio powers and possibly detections of mini-haloes are linked to star formation and merger histories of the clusters.