Multi-frequency observations and analysis of Abell 1682

• Main Author: Khanye, Nthabiseng Fortunate
• Format: Others
• Language: en
• Published: 2019
• Online Access: https://hdl.handle.net/10539/26734

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science, 2018 === The radio emissions observed in galaxy clusters is usually attributed to the effects of shocks, turbulence and re-acceleration of relativistic particles in magnetic fields which permeate the cluster atmospheres. Clusters contain different sources of radio emissions ranging from active galactic nuclei (AGN) to enormous regions of diffuse radio synchrotron emission known as radio halos and relics. In this thesis multi-frequency observations are used to study the astrophysical origin and properties of the extended radio emission of the A1682 galaxy cluster detected in the LOFAR Two-metre Sky Survey. The first study of the cluster by The Giant Metrewave Radio Telescope (GMRT) suggested that the cluster might host a candidate radio halo and candidate relics due to its excessive radio emission. We found that the main radio emission is associated to a bright radio galaxy (identified with the source A1304+4649A in the NASA Extragalactic Database) with its bended radio jets/lobes. Since the nature of the candidate relic is not well understood, in the second part of the thesis we explore the possibility of a gravitational lensing galaxy and the annihilation of dark matter particles as possible sources of the diffuse radio emission. Publicly available archival images from low frequency radio surveys (mainly LoTSS, NRAO VLA sky survey and GMRT Sky Survey), millimeter (Planck Legacy Archive), optical (Hubble Legacy Archive) and X-ray observations (Chandra Data Archive) are used for the extensive study of this complex cluster. === XL2019