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Showing 1 to 11 of 11 for “"active galaxies"”.
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Infrared to millimetre observations of active galaxies
… from the nuclear regions of a number of active galaxies. In particular many observations have been made for the first time in the submillimetre regime. The observing methods at these wavelengths and the unique astrophysical information on the nature of active galaxies that results from …
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Millimetre and Submillimetre continuum imaging studies of nearby active galaxies
… imaging observations of the four, nearby active galaxies Cygnus A, NCC 4374, Centaurus A and M 82. These were undertaken using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope in Hawaii. The study focused on the properties of the cool to cold dust …
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The Mass-Pitch Angle Relation for Three High Redshift Active Galaxies Selected from the GOODS Field
… gravitational wells at the center of all galaxies. These supermassive black holes at a galaxies nucleus formed in the company of the other features making up the galaxy, particularly spiral arms. With nearby galaxies showing a relationship between the spiral arm pitch angle and that …
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Astrophysical maser radiation from Keplerian disks near active galactic nuclei
… emerging from gaseous disks at the nuclei of active galaxies. In at least one galaxy (NGC 4258), such maser radiation is observed and arises from a disk around a presumed massive black hole. The heating, cooling, and excitation mechanisms necessary for creating the physical conditions and …
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X-ray and optical properties of X-ray luminous active galactic nuclei
… below 2 keV into single point sources, mainly active galaxies. The cosmic X-ray background is the integration of all accreting super-massive (several million solar masses) black holes in the centre of active galaxies over cosmic time. Synthesis models need further populations of X-ray absorbed …
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Multifrequency observations of blazars
Blazars are a class of active galactic nuclei (AGN). Active galaxies are those that host compact sources of non-thermal radiation in their nuclear regions and are usually classified as being radio-loud or radio-quiet. The nature of the central source is ullcertain, but arguments based on energy …
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The formation of enhanced, low-ionization emission in galactic halos
… unusual excitation in the halos of nearby spiral galaxies. This has led to speculation concerning the excitation mechanisms operating at high galactic latitudes, including exotic processes involving nonequilibrium physics, local grain destruction and decaying dark matter. We demonstrate that the …
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Searching for binary and dual supermassive black holes in large surveys
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-12-04 without embargo terms
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Simulations of active galactic nucleus feedback in the cores of galaxy clusters
… a new subgrid model and studying feedback from active galactic nuclei (AGN) using adaptive mesh refinement (AMR) hydrodynamics simulations of the cores of galaxy clusters. Modeling of feedback from AGN that consist of central super-massive black holes (SMBH) in galaxy clusters through …
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Robotic Polarimetry of Blazars
… of this thesis was the study of radio-loud, active galaxies. These galaxies house relativistic jets at their centres, powered by accretion onto a super massive black hole. The focus was on the optical flux and polarised emission produced by these powerful jets. An automated pipeline was …
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Unveiling fundamental physics with high-resolution X-ray spectroscopy of Active Galactic Nuclei.
… the use of high-resolution spectroscopy of active galactic nuclei (AGNs) to probe fundamental physics. It focuses on the study of axion-like particles (ALPs) and the spin of supermassive black holes (SMBHs). Chapter 1 starts with a review of black holes as mathematical and astronomical …