Abstract Details

Name: Majidul Rahaman
Affiliation: Indian Institute of Technology Indore
Conference ID: ASI2021_345
Title : Investigating the origin of diffuse radio emission in galaxy clusters using Chandra X-ray observations
Authors and Co-Authors : Mr. Majidul Rahaman (IIT Indore), Dr. Abhirup Datta (IIT Indore), Mr. Ramij Raja (IIT Indore)
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : Collisions between galaxy clusters provide a unique opportunity to study matter in a parameter space that cannot be explored in our laboratories on Earth. Cluster formation is hierarchical, and clusters grow mostly by merging. Mergers of two massive clusters are the most energetic events in the Universe after the Big Bang; hence they provide a unique laboratory to study cluster physics. The two main mass components in clusters behave differently during collisions: the dark matter is nearly collisionless, responding only to gravity, while the gas is subject to pressure forces and dissipation, and shocks and turbulence are developed during collisions. Cluster mergers stir the intracluster medium creating shocks and turbulence, which are illuminated by diffuse radio features called halos, relics, and radio phoenixes. However, shocks and turbulences are detected via signatures in the thermal X-ray emission. Disturbed morphologies in X-ray surface brightness and temperatures are direct evidence for cluster mergers. Therefore, the study of the X-ray observations can lead to a deeper understanding of the origin of diffuse radio emissions in the galaxy clusters. We present results from multi-wavelength (radio and X-ray) observations of two merging galaxy clusters AS1063, A1914, and A85. We produce thermodynamic maps for all the clusters using the ACB, WVT, and Contour binning method from Chandra X-ray archival data. We report the detection of three shock waves in the A1914 cluster and investigated if these shocks are related to the origin of radio phoenix and radio halo present in the cluster. In A85, low-frequency GMRT observations (325 MHz) have revealed a complex and filamentary diffuse radio phoenix at the place of the infalling southwest subcluster. We also detect an X-ray shock near the radio phoenix. We find the observational evidence of the possible connection between an X-ray shock and the radio phoenix for the first time.