RADIO EMISSION FROM LOW MASS ACTIVE GALACTIC NUCLEI

Massive black holes of a few million to billion solar masses lurk at the centers of the most present-day massive galaxies but their origin is still unknown. The low mass galaxies (M* ~ 3x109 Mʘ ) hosting black holes with masses ranging from 103 to 105 Mʘ are ideal laboratories to test the models of black hole formation and they may help in understanding the coevolution of central black holes with their host galaxies. In this thesis, we have developed a detailed theoretical model/framework to estimate the radio emission from low mass active galactic nuclei (AGN). We also compute the contribution of radio emission from HII regions and supernova remnants in the host galaxy. Our estimated radio fluxes for AGN of 105 -107 Mʘ range from 0.6-2000 nJy at redshift 10 assuming the Eddington limited accretion. The most recent observations by the James Webb Space Telescope have unveiled the presence of low mass AGN at high redshift. We predict that these newly observed sources can be detected in radio with upcoming radio telescopes such as next-generation Very Large Array (ngVLA) and the Square Kilometer Array (SKA) for integration times of 1-100 hours. These observations will unambiguously confirm the existence of AGN.