Abstract Details
| Name: Prateek Gupta Affiliation: S P Pune University Conference ID: ASI2019_461 Title : Detection possibilities of 'Galaxy groups' using Numerical modelling of Radio emission & Large Scale Cosmological Simulation Authors and Co-Authors : Prateek Gupta, Department of Physics, S P Pune University, Pune Surajit Paul, Department of Physics, S P Pune University, Pune Reju Sam John, IUCAA, Pune Abstract Type : Oral Abstract Category : General Relativity and Cosmology Abstract : Galaxy groups are usually called the scaled-down versions of Galaxy clusters. The observed steep mass scaling of radio power from the available high mass galaxy clusters has ruled out the prospect of detection of ’galaxy groups’. But, reported simulations and observations of thermal emissions suggest groups are merger prone, thus non-virialised, indicating better visibility in the non-thermal emissions. Detection of non-thermal radio emissions from them would help us to understand the scale-dependent effectiveness of particle acceleration mechanisms, as well as, being younger and cooler, groups can be a unique laboratory to test the models of cosmic magnetism. They can also be the potential source of Warm-Hot Intergalactic Medium (WHIM). So, in this work, we present a simple model for computing magnetic field and for the first time a model for radio synchrotron emission combining the diffusive shock acceleration (DSA) and reconnection mediated turbulent re-acceleration (Turbulent Reconnection Acceleration: TRA) electrons using Adaptive Mesh Refinement (AMR), grid-based hybrid (N-body + Hydro-dynamical) cosmological simulations. From a sample of more than 600 simulated objects in wide mass range (≥ 10^{13} to 2 × 10^{15} Msun), we found that the total radio power from TRA and DSA electrons can only fit reasonably well to all the observed ‘radio halos’ at high masses. This significantly improves our understanding of radio halo emission and allow us to extend the results to further smaller masses. We got a new mass scaling of P_{1.4 GHz} ∝ M_{500}^{2.39±0.04} and a correlation scale of P_{1.4 GHz} ∝ L_X^{1.31±0.04}. Also significantly, groups below 10^{14} Msun reveals the existence of 10s of nano-Gauss to a sub-μG magnetic field and radio power of about 10^{19−23} W/Hz, much higher than what existing mass scaling predicts, indicating possible detection by existing and aplenty with the future radio telescopes. |