The Hypothetical Population of Intermediate Mass Black Holes In the Galactic Nucleus: Could a steady state of intermediate-mass black holes exist in the galactic centre?

This thesis aims to alleviate the final parsec problem by investigating the hypothetical intermediate-mass black hole environment lying at the cores of galaxies, a model first proposed by Ebisuzaki et al. (2001) [1]. Although intermediate-mass black holes remain undetected, their nature could be the key to understanding supermassive black hole formation. If they are indeed present at the hearts of galaxies, their mutual interactions encourage supermassive black hole-intermediate-mass black hole merging events. Such merging events bypass theoretical constraints placed by binary dynamics and the Eddington limit, allowing for supermassive black holes to grow into their colossal sizes, and could potentially help explain their existence in the early stages of the Universe’s life. We investigate this model using both a Newtonian (Hermite) and post-Newtonian (HermiteGRX) algorithm. The post-Newtonian algorithm incorporates terms up to order 2.5, allowing it to model gravitational wave...Show moreThis thesis aims to alleviate the final parsec problem by investigating the hypothetical intermediate-mass black hole environment lying at the cores of galaxies, a model first proposed by Ebisuzaki et al. (2001) [1]. Although intermediate-mass black holes remain undetected, their nature could be the key to understanding supermassive black hole formation. If they are indeed present at the hearts of galaxies, their mutual interactions encourage supermassive black hole-intermediate-mass black hole merging events. Such merging events bypass theoretical constraints placed by binary dynamics and the Eddington limit, allowing for supermassive black holes to grow into their colossal sizes, and could potentially help explain their existence in the early stages of the Universe’s life. We investigate this model using both a Newtonian (Hermite) and post-Newtonian (HermiteGRX) algorithm. The post-Newtonian algorithm incorporates terms up to order 2.5, allowing it to model gravitational wave emission, which acts as an energy sink source and encourages merging events. In addition to comparing the results found using either algorithm, we forecast its corresponding gravitational wave events. More specifically, assuming a steady intermediate-mass black hole infall rate of one every 7 Myr, we predict a population of NIMBH = 15∼20 residing at the inner 0.4pc of the Milky Way galaxy. In turn, the future gravitational wave interferometer LISA and the proposed one µAres will be able to detect up to 926 supermassive black hole-intermediate-mass black hole merging events per year up to a redshift z ≤ 3. This value is three orders of magnitude larger than those found in various literature ([2]; [3]; [4]; [5]) due to the lack of observation of intermediate-mass black hole leaving a large parameter space in such analysis.Show less

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The Hypothetical Population of Intermediate Mass Black Holes In the Galactic Nucleus: Could a steady state of intermediate-mass black holes exist in the galactic centre?