Abstract Details

Conference ID: ASI2017_768
Title : Revealing the unseen Universe by numerical modelling of radio emission
Authors and Co-Authors : Surajit Paul, Dept of Physics, University of Pune (SPPU), Pune Reju Sam John, P.E.C., Pondicherry University
Abstract Type : Poster
Abstract Category : Extragalactic astronomy
Abstract : The Universe appears as the cosmic-web structure at large-scales (>few tens of Mpc) where Galaxy clusters form the knots in the complex filamentary network (web) which drains out the matter (dark matter and baryons) from voids to feed its respective knots. As most of the matter is possibly processed first time in the filaments and the outskirts of Galaxy clusters, those region should contain a wealth of information about the energetics of the cosmic structures. Kinetic energy released during structure formation dissipates in the intra-cluster-medium (ICM) by shock thermalization and turbulence generation. This turbulence due to feeding of material can cause the local magnetic field which can be amplified by shock waves in ICM which are generated during the formation of these structures. These shock waves also accelerate the significant population of charge particles by diffusive shock acceleration (DSA) mechanism. Due to baroclinic instability at the junction of the filaments and Galaxy clusters, a significant turbulence is generated which further amplify the magnetic field by dynamo action and also re-accelerate the charge particles by turbulent re-acceleration (TRA) mechanism which in turn produce Synchrotron emission. This synchrotron radio emission could help in tracing back the dynamical history of these structures. In this work, we deployed both of our models (DSA and TRA) for computing radio emission from Large Scale Structures (LSS) using Adaptive Mesh Refinement (AMR), grid based hybrid (N-body + Hydro -dynamical) cosmological simulations. Computation is being done on grid parameters and a proper weight has been used to nullify the effect of complicated resolution pattern of an AMR simulation. Finally, we have created the synthetic radio maps, for each model and also with combined effect, and clearly predicted the possible detectable sources with the upcoming telescope (SKA). This work of ours has resolved many issues related to the observational aspect as well as yet to observe. It explained the observed radio relics found at few Mega parsec away from Galaxy cluster as well as predicted some very interesting radio structures, existence of complex filamentary network, Warm-hot intergalactic medium (WHIM) which is yet to reveal by the new generation telescopes in near future. Detection of filaments and WHIM will give us the complete structure of our universe as well as will solve the problem of missing baryons.