scholarly journals Gravitational radiation from a spinning compact object around a supermassive Kerr black hole in circular orbit

2010 ◽  
Vol 82 (8) ◽  
Author(s):  
Wen-Biao Han
Keyword(s):  
Black Hole ◽  
Gravitational Radiation ◽  
Circular Orbit ◽  
Kerr Black Hole ◽  
Compact Object

scholarly journals Magnetized Particle Motion in γ-Spacetime in a Magnetic Field

Galaxies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 76
Author(s):  
Ahmadjon Abdujabbarov ◽  
Javlon Rayimbaev ◽  
Farruh Atamurotov ◽  
Bobomurat Ahmedov
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Center Of Mass ◽  
Kerr Black Hole ◽  
Compact Object ◽  
Magnetic Interaction ◽  
Mass Energy ◽  
Circular Orbits ◽  
Center Of Mass Energy ◽  
Astrophysical Scenario

In the present work we explored the dynamics of magnetized particles around the compact object in γ-spacetime in the presence of an external asymptotically-uniform magnetic field. The analysis of the circular orbits of magnetized particles around the compact object in the spacetime of a γ-object immersed in the external magnetic field has shown that the area of stable circular orbits of magnetized particles increases with the increase of γ-parameter. We have also investigated the acceleration of the magnetized particles near the γ-object and shown that the center-of-mass energy of colliding magnetized particles increases with the increase of γ-parameter. Finally, we have applied the obtained results to the astrophysical scenario and shown that the values of γ-parameter in the range of γ∈(0.5,1) can mimic the spin of Kerr black hole up to a≃0.85, while the magnetic interaction can mimic the γ-parameter at γ∈(0.8,1) and spin of a Kerr black hole up to a≃0.3.

scholarly journals Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA*

2018 ◽  
Vol 618 ◽  
pp. L10 ◽  
Author(s):  
◽  
R. Abuter ◽  
A. Amorim ◽  
M. Bauböck ◽  
J. P. Berger ◽  
...  
Keyword(s):  
Black Hole ◽  
Circular Orbit ◽  
Near Infrared ◽  
Hot Spot ◽  
Kerr Black Hole ◽  
Polarization Angle ◽  
Gravitational Radius ◽  
Massive Black Hole ◽  
Poloidal Magnetic Field ◽  
Continuous Rotation

We report the detection of continuous positional and polarization changes of the compact source SgrA* in high states (“flares”) of its variable near-infrared emission with the near-infrared GRAVITY-Very Large Telescope Interferometer (VLTI) beam-combining instrument. In three prominent bright flares, the position centroids exhibit clockwise looped motion on the sky, on scales of typically 150 μas over a few tens of minutes, corresponding to about 30% the speed of light. At the same time, the flares exhibit continuous rotation of the polarization angle, with about the same 45(±15) min period as that of the centroid motions. Modelling with relativistic ray tracing shows that these findings are all consistent with a near face-on, circular orbit of a compact polarized “hot spot” of infrared synchrotron emission at approximately six to ten times the gravitational radius of a black hole of 4 million solar masses. This corresponds to the region just outside the innermost, stable, prograde circular orbit (ISCO) of a Schwarzschild–Kerr black hole, or near the retrograde ISCO of a highly spun-up Kerr hole. The polarization signature is consistent with orbital motion in a strong poloidal magnetic field.

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