Date of Defense
9-11-2023 3:00 PM
Location
F3-223
Document Type
Thesis Defense
Degree Name
Master of Science in Space Science (MSSS)
College
COS
Department
Physics
First Advisor
Dr. Mohammad Abdul Latif
Keywords
Active galactic nuclei, Black holes, Radio emission, Radio flux, Luminosity, Fundamental planes, Black hole masses, Accretion rates.
Abstract
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.
Included in
RADIO EMISSION FROM LOW MASS ACTIVE GALACTIC NUCLEI
F3-223
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.