Browsing by Author "Shiferaw, Abera"

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    Generation and Collimation Mechanisms of Relativistic Jets in AGN
    (Addis Ababa University, 2006-06) Shiferaw, Abera; Jha, Ramanand (Professor)
    Most of the phenomenon performed by active galaxies are left uncovered among which highly collimated jet-like out°ows, that span hounders of Kpc to Mpc via interstellar medium, is the one. Our current research, which is fully analytic, is targeted on ¯nding the plausible mechanism of jets generation and collimation in these Mysterious active galaxies. In this work, Kerr geometry is preferred to describe the dynamics of electromagnetic ¯eld and plasma °uid around rotating Kerr black hole. we ¯nd out that the force-free region, in the immediate neighborhood of rotating black hole, is the site where jets generation and launching are fabricated. Toroidal magnetic ¯eld and centrifugal force, on the accreting plasma °uid, are the key elements for the generation and launching of jets. Collimation of jets is the responsibility of: magnetic hoop stress, radiation pressure, from the accretion disk, and centrifugal force. Also, magnetic ¯eld is found to be crucially important in extracting the spin energy of the black hole. Energy and angular momentum are continuously supplied to the jets through di®erential rotation
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    Generation and collimation mechanisms of relativistic jets in AGN
    (Addis Ababa., 2006-06) Shiferaw, Abera; Jha, Ramanand (PhD)
    io. lost. of the phenomenon performed by active gala.xies are lef\' uncO\'crccl among which highly collimated jet-like outflows, that span hounders of Kpc to ~ Ipc via interstellar medium, is l.hc one. OUf current. research, which is fully analytic, is targeted on finding t he plausible mechanism of jets generation and collimation in Lhcse :-' Iysteriolls active gala.xies. In this work, Kerr geomet.ry is preferred to describe t.he dynamics of electromagnetic field and plasma fluid around rotating Kerr black hole. we find out. that the force-free region, in the immediate neighborhood of rotating black hole, is the site where jets generation and launching are fabricated. Toroidal magnetic field and centrifugal force, on the accreting plasma fluid. are "he key elements for t.he generation and launching of jets. Collimat.ion of jets is the responsibility of: magnetic hoop stress, radiation pressure, from t.he accretion disk, and centrifugal force. Also, magnetic field is found to be crucially important. in extract.ing the spin energy of t.he black hole. Energy and angular momentum are continuously supplied to t he jets through di fferential rotation. viii