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The largest galaxies, and in particular central galaxies in clusters, offer unique insight into understanding the mechanism for the growth of nuclear black holes. We present Hubble Space Telescope kinematics for NGC1399, the central galaxy in Fornax. We find the best-fit model contains a black hole of 5.1 +-0.7 x 10^8 Msun (at a distance of 21.1 Mpc), a factor of over 2 below the correlation of black hole mass and velocity dispersion. We also find a dramatic signature for central tangential anisotropy. The velocity profiles on adjacent sides 0.5 away from the nucleus show strong bimodality, and the central spectrum shows a large drop in the dispersion. Both of these observations point to an orbital distribution that is tangentially biased. The best-fit orbital model suggests a ratio of the tangential to radial internal velocity dispersions of three. This ratio is the largest seen in any galaxy to date and will provide an important measure for the mode by which the central black hole has grown.
We study the $mathsf{SL}(2)$ transformation properties of spherically symmetric perturbations of the Bertotti-Robinson universe and identify an invariant $mu$ that characterizes the backreaction of these linear solutions. The only backreaction allowe
We use the gravitational wave signals from binary black hole merger events observed by LIGO and Virgo to reconstruct the underlying mass and spin distributions of the population of merging black holes. We reconstruct the population using the mixture
We report on a study that finds a positive correlation between black hole mass and variability amplitude in quasars. Roughly 100 quasars at z<0.75 were selected by matching objects from the QUEST1 Variability Survey with broad-lined objects from the
We discuss the properties of the effective-one-body (EOB) multipolar gravitational waveform emitted by nonspinning black-hole binaries of masses $mu$ and $M$ in the extreme-mass-ratio limit, $mu/M= ull 1$. We focus on the transition from quasicircula
It is known that the Meissner-like effect is seen in a magnetosphere without an electric current in black hole spacetime: no non-monopole component of magnetic flux penetrates the event horizon if the black hole is extreme. In this paper, in order to