TY - JOUR
T1 - Measurement of the Kerr spin parameter by observation of a compact object's shadow
AU - Hioki, Kenta
AU - Maeda, Kei Ichi
PY - 2009/8/6
Y1 - 2009/8/6
N2 - A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study how to determine the spin parameter and the inclination angle by observing the apparent shape of the shadow, which is distorted mainly by those two parameters. Defining some observables characterizing the apparent shape (its radius and distortion parameter), we find that the spin parameter and inclination angle of a Kerr black hole can be determined by the observation. This technique is also extended to the case of a Kerr naked singularity.
AB - A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study how to determine the spin parameter and the inclination angle by observing the apparent shape of the shadow, which is distorted mainly by those two parameters. Defining some observables characterizing the apparent shape (its radius and distortion parameter), we find that the spin parameter and inclination angle of a Kerr black hole can be determined by the observation. This technique is also extended to the case of a Kerr naked singularity.
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U2 - 10.1103/PhysRevD.80.024042
DO - 10.1103/PhysRevD.80.024042
M3 - Article
AN - SCOPUS:69249135441
SN - 1550-7998
VL - 80
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 2
M1 - 024042
ER -