Abstract Details
| Name: Reju John Affiliation: IUCAA, Pune Conference ID: ASI2019_37 Title : Study of Energy Distribution in Evolving Dynamical States of Galaxy Clusters and Groups Authors and Co-Authors : Reju Sam John Abstract Type : Oral Abstract Category : Thesis Abstract : Galaxy clusters are known to be the reservoirs of Cosmic Rays (CRs), mostly inferred from theoretical calculations or detection of CR derived observables. Though CR electrons have been detected through radio emissions, CR protons and its derivative gamma rays remained undetected. CR acceleration in clusters is mostly attributed to its dynamical activities that produce shocks. Shocks in clusters emerge out of merger or accretion but, which one is more effective? at which dynamical phase? and why? So, in quest of answers, we study the detail evolution of cosmic ray emission in the galaxy clusters using cosmological simulations with enzo code. Defining appropriate dynamical states using the concept of virialization, we have studied a sample of merging and non-merging clusters. We report that the merger shocks (Mach, M = 2-5) are the most effective CR producers in clusters. Clusters once merged, permanently deviate from CR and X-ray mass scaling of non-merging systems, enabling us to use it as a tool to determine the state of merger. Through a temporal and spatial evolution study, we found a strong correlation between cluster merger dynamics and CR injection. We have observed that the brightest phase of X-ray and CR emission from clusters occur respectively about 1.0 and 1.5 Gyr after every merger. This finding of delay in CR injection peaks can be a useful information to shed light upon the brightest phase of gamma-rays from clusters of galaxies. This may also be a guiding information to select appropriate targets for gamma-ray detection from clusters. Not only that, but we have also shown that galaxy groups that are supposed to be Gamma quiet are rather comparatively more active than we thought and follow different scaling laws than the clusters and they can also be seen in non-thermal energies. |