Results 71 to 80 of about 38,906 (246)
, 2012 We consider test planet and photon orbits of the third kind inside a black hole, which are stable, periodic and neither come out of the black hole nor terminate at the singularity.
B. Carter +6 more
core +1 more source
Constraints on alternatives to supermassive black holes [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2006 Abstract Observations of the centres of galaxies continue to evolve, and it is useful to take a fresh look at the constraints that exist on alternatives to supermassive black holes at their centres. We discuss constraints complementary to those of Maoz and demonstrate that an extremely wide range of other possibilities can be excluded ...
M. Coleman Miller, M. Coleman Miller
openaire +4 more sources
Dark energy and supermassive black holes [PDF]
Physical Review D, 2004 This paper deals with a cosmological model in which the universe is filled with tachyon dark energy in order to describe current and future accelerating expansion. We obtain that the simplest condition for the regime of phantom energy to occur in this scenario is that the scalar field be Wick rotated to imaginary values which correspond to an axionic ...
openaire +4 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
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 +1 more
doaj +1 more source
The Illustris Simulation: Supermassive Black Hole - Galaxy Connection Beyond the Bulge
, 2017 We study the spiral arm morphology of a sample of the local spiral galaxies in the Illustris simulation and explore the supermassive black hole - galaxy connection beyond the bulge (e.g., spiral arm pitch angle, total stellar mass, dark matter mass, and ...
Berrier, Joel C. +5 more
core +1 more source
Supermassive black holes in the early Universe [PDF]
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2015 The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only approximately 900 Myr after the big bang, and only approximately 500 Myr beyond the formation of Pop II and III stars.
F. Melia, T. M. McClintock
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
The Black Hole Particle Accelerator as a Machine to make Baby Universes [PDF]
, 2013 General relativity predicts that the inner horizon of an astronomically realistic rotating black hole is subject to the mass inflation instability. The inflationary instability acts like a gravity-powered particle accelerator of extraordinary power ...
Hamilton, A. J. S.
core
Supermassive black holes in galactic bulges [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2008 Abstract Growing evidence indicate supermassive black holes (SMBHs) in a mass range of MBH∼ 106–1010 M⊙ lurking in central stellar bulges of galaxies. Extensive observations reveal fairly tight power laws of MBH versus the mean stellar velocity dispersion σ of the host stellar bulge.
Yu-Qing Lou +3 more
openaire +3 more sources