Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication
- Publication Type
Articles 1 - 5 of 5
Full-Text Articles in Astrophysics and Astronomy
Monitoring Agns With H-Beta Asymmetry: Markarian 841, Samuel J. Schonsberg
Monitoring Agns With H-Beta Asymmetry: Markarian 841, Samuel J. Schonsberg
Undergraduate Theses, Professional Papers, and Capstone Artifacts
Quasars are among the most luminous objects in the Universe, and the mechanism behind their luminosity was shrouded in mystery decades after their discovery. Since then, we have found that these objects are active galactic nuclei (AGN), which are powered by actively-feeding super massive black holes at the center of a galaxy. But we still know fairly little about the structure and motion of the material surrounding active super massive black holes, and most of these objects are not resolvable by conventional observations. We use a technique called reverberation mapping, which is traditionally used only as a mass determination …
Test Particle Motion Around Brany Black Hole Immersed In An External Asymptotically Uniform Magnetic Field, Djavlanbek Rayimbaev, Azamjon Rakhmatov, Satimbay Palvanov, Ahror Mamadjanov
Test Particle Motion Around Brany Black Hole Immersed In An External Asymptotically Uniform Magnetic Field, Djavlanbek Rayimbaev, Azamjon Rakhmatov, Satimbay Palvanov, Ahror Mamadjanov
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences
We investigate circular motion of charged and neutral particles around non-rotating black hole immersed in an external asymptotically uniform magnetic field. The effects of braneworlds on innermost circular stable orbits have been considered. Shown that innermost circular orbits (ISCO) decreases in decreasence of both brane charge and particle charge. Moreover, we have investigated energy extraction from black holes in braneworld through collision of two particles. Obtained that the presence of the brane charge parameter causes to decrease of the value of center of mass energy of colliding two charged particles, it means the brane charge acts as an additional gravity.
Exact Solutions In Gravity: A Journey Through Spacetime With The Kerr-Schild Ansatz, Benjamin Ett
Exact Solutions In Gravity: A Journey Through Spacetime With The Kerr-Schild Ansatz, Benjamin Ett
Doctoral Dissertations
The Kerr-Schild metric ansatz can be expressed in the form $g_{ab} = \gbar_{ab}+\lambda k_ak_b$, where $\gbar_{ab}$ is a background metric satisfying Einstein's equations, $k_a$ is a null-vector, and $\lambda$ is a free parameter. It was discovered in 1963 while searching for the elusive rotating black hole solutions to Einstein's equations, fifty years after the static solution was found and Einstein first formulated his theory of general relativity. While the ansatz has proved an excellent tool in the search for new exact solutions since then, its scope is limited, particularly with respect to higher dimensional theories. In this thesis, we present …
Hadamard Renormalisation Of The Stress Energy Tensor On The Horizons Of A Spherically Symmetric Black Hole Space-Time, Cormac Breen, Adrian Ottewill
Hadamard Renormalisation Of The Stress Energy Tensor On The Horizons Of A Spherically Symmetric Black Hole Space-Time, Cormac Breen, Adrian Ottewill
Articles
We consider a quantum field which is in a Hartle-Hawking state propagating in a general spherically symmetric black hole space-time. We make use of uniform approximations to the radial equation to calculate the components of the stress tensor, renormalized using the Hadamard form of the Green's function, on the horizons of this space-time. We then specialize these results to the case of the `lukewarm' Reissner-Nordstrom-de Sitter black hole and derive some conditions on the stress tensor for the regularity of the Hartle-Hawking state
Central Compact Objects, Trevor Meek
Central Compact Objects, Trevor Meek
Physics
Central compact objects (CCOs) are point-like sources found near the center of supernova remnants (SNRs). They emit X-rays, but show no radio or gamma ray counterpart. Typical CCO candidates have emission radii on the order of 0.2-3.0 km. This is much smaller than the typical radius of a neutron star, making CCOs a difficult astronomical phenomenon to identify.