Results 81 to 90 of about 37,815 (249)

Hierarchical build-up of galactic bulges and the merging rate of supermassive binary black holes

, 2003
The hierarchical build-up of galactic bulges should lead to the build-up of present-day supermassive black holes by a mixture of gas accretion and merging of supermassive black holes.
Begelman M, Begelman M, Bender P, Bernardi M, Gerssen J, Haehnelt M G, Haehnelt M G, Haehnelt M G, Martin G Haehnelt, Milosavljevic M, Soltan A, Yu Q   +11 more
core   +1 more source

Asymptotically‐Flat Black Hole Solutions in Symmergent Gravity

Fortschritte der Physik, Volume 72, Issue 4, April 2024.
Abstract Symmergent gravity is an emergent gravity model with an R+R2$R+R^2$ curvature sector and an extended particle sector having new particles beyond the known ones. With constant scalar curvature, asymptotically flat black hole solutions are known to have no sensitivity to the quadratic curvature term (coefficient of R2$R^2$). With variable scalar
Beyhan Puliçe, Reggie C. Pantig, Ali Övgün, Durmuş Demir   +3 more
wiley   +1 more source

Fundamental physics opportunities with future ground-based mm/sub-mm VLBI arrays

Living Reviews in Relativity
The Event Horizon Telescope (EHT) Collaboration recently published the first images of the supermassive black holes in the cores of the Messier 87 and Milky Way galaxies.
Dimitry Ayzenberg, Lindy Blackburn, Richard Brito, Silke Britzen, Avery E. Broderick, Raúl Carballo-Rubio, Vitor Cardoso, Andrew Chael, Koushik Chatterjee, Yifan Chen, Pedro V. P. Cunha, Hooman Davoudiasl, Peter B. Denton, Sheperd S. Doeleman, Astrid Eichhorn, Marshall Eubanks, Yun Fang, Arianna Foschi, Christian M. Fromm, Peter Galison, Sushant G. Ghosh, Roman Gold, Leonid I. Gurvits, Shahar Hadar, Aaron Held, Janice Houston, Yichao Hu, Michael D. Johnson, Prashant Kocherlakota, Priyamvada Natarajan, Héctor Olivares, Daniel Palumbo, Dominic W. Pesce, Surjeet Rajendran, Rittick Roy, Saurabh, Lijing Shao, Shammi Tahura, Aditya Tamar, Paul Tiede, Frédéric H. Vincent, Luca Visinelli, Zhiren Wang, Maciek Wielgus, Xiao Xue, Kadri Yakut, Huan Yang, Ziri Younsi   +47 more
doaj   +1 more source

Gravitational Larmor precession

European Physical Journal C: Particles and Fields, 2023
Inspired by the reported existence of substantive magnetic fields in the vicinity of the central supermassive black holes in Sagittarius A* and Messier 87*, we consider test particle motion in the spacetime close to a generic spherical black hole in the ...
Chandrachur Chakraborty, Parthasarathi Majumdar   +1 more
doaj   +1 more source

A Supermassive Black Hole in an Ultracompact Dwarf Galaxy

, 2014
Ultracompact dwarf galaxies (UCDs) are among the densest stellar systems in the universe. These systems have masses up to 200 million solar masses, but half light radii of just 3-50 parsecs.
Baumgardt, Holger, Bosch, Remco van den, Brodie, Jean, Brok, Mark den, Chilingarian, Igor, Frank, Matthias, Hilker, Michael, McDermid, Richard, Mieske, Steffen, Neumayer, Nadine, Seth, Anil, Spitler, Lee, Strader, Jay, Walsh, Jonelle L.   +13 more
core   +1 more source

Differential rotation in compact objects with hyperons and delta isobars

Astronomische Nachrichten, Volume 345, Issue 2-3, February-March 2024.
Abstract Neutron stars may experience differential rotation on short, dynamical timescales following extreme astrophysical events like binary neutron star mergers. In this work, the masses and radii of differentially rotating neutron star models are computed.
Delaney Farrell, Fridolin Weber, Jia Jie Li, Armen Sedrakian   +3 more
wiley   +1 more source

Spectroscopy of the near-nuclear regions of Cygnus A: estimating the mass of the supermassive black hole [PDF]

, 2003
We use a combination of high spatial resolution optical and near-IR spectroscopic data to make a detailed study of the kinematics of the NLR gas in the near-nuclear regions of the powerful, FRII radio galaxy Cygnus A (z=0.0560), with the overall goal of ...
A. Marconi, Antonucci, Bach, Barth, Barthel, Blanco, Bower, Bruzual, C. Tadhunter, Carilli, Carilli, Conway, Corbett, D. Axon, Djorgovski, Elvis, Faber, Fabian, Ferrarese, Fosbury, Franceschini, Gebhardt, Ghisellini, Jackson, K. Wills, Kaspi, Kellerman, Kormendy, Krichbaum, Maloney, Marconi, Marconi, Marconi, McLean, McLure, McLure, N. Jackson, Ogle, Osterbrock, Owen, Reynolds, Silk, Simkin, Sorathia, Spinrad, Stockton, T. G. Robinson, Tadhunter, Tadhunter, Tadhunter, Tadhunter, Tadhunter, Taylor, Thornton, Tremaine, Ueno, van der Marel, Verdoes Kleijn, Verdoes Kleijn, Ward, Young   +60 more
core   +3 more sources

Supermassive black holes in galactic nuclei

AIP Conference Proceedings, 2001
We review the motivation and search for supermassive black holes (BHs) in galaxies. Energetic nuclear activity provides indirect but compelling evidence for BH engines. Ground-based dynamical searches for central dark objects are reviewed in Kormendy & Richstone (1995, ARA&A, 33, 581). Here we provide an update of results from the HST.
John Kormendy, Karl Gebhardt
openaire   +3 more sources

Nuclear Spirals and Supermassive Black Holes [PDF]

Symposium - International Astronomical Union, 2004
We have performed SPH simulations for the response of the gaseous disks to the imposed potentials including those from bars and SMBHs. Evolution of the nuclear regions of gaseous disks depends critically on the masses of SMBHs as well as the sound speed in the gas.
Hong Bae Ann, Parijat Thakur
openaire   +3 more sources

Null Geodesics and Strong Field Gravitational Lensing in a String Cloud Background

Advances in High Energy Physics, 2015
This paper is devoted to studying two interesting issues of a black hole with string cloud background. Firstly, we investigate null geodesics and find unstable orbital motion of particles. Secondly, we calculate deflection angle in strong field limit. We
M. Sharif, Sehrish Iftikhar
doaj   +1 more source