PIRSA:20120027

Photon Emission from Circular Equatorial Orbiters around Kerr Black Holes

Gates, D. (2020). Photon Emission from Circular Equatorial Orbiters around Kerr Black Holes. Perimeter Institute. https://pirsa.org/20120027

Gates, Delilah. Photon Emission from Circular Equatorial Orbiters around Kerr Black Holes. Perimeter Institute, Dec. 17, 2020, https://pirsa.org/20120027 

          @misc{ pirsa_PIRSA:20120027,
            doi = {10.48660/20120027},
            url = {https://pirsa.org/20120027},
            author = {Gates, Delilah},
            keywords = {Strong Gravity},
            language = {en},
            title = {Photon Emission from Circular Equatorial Orbiters around Kerr Black Holes},
            publisher = {Perimeter Institute},
            year = {2020},
            month = {dec},
            note = {PIRSA:20120027 see, \url{https://pirsa.org}}
          }

Delilah Gates Princeton University

DOI 10.48660/20120027
Collection
Talk Type Scientific Series
Subject

Abstract

We consider monochromatic and isotropic photon emission from circular equatorial Kerr orbiters. We calculate the critical curve delineating the region of photon escape from that of photon capture in each emitter’s sky, allowing us to derive analytic expressions for the photon escape probability and the redshift-dependent total flux collected on the celestial sphere as a function of emission radius and black hole parameters. This critical curve generalizes to finite orbital radius the usual Kerr critical curve and displays interesting features in the limit of high spin. These results confirm that the near-horizon geometry of a high-spin black hole is in principle observable.