BH1-2-3 - (BH1) Binary Black Holes as Sources of Multi-messenger Astronomy - (BH2) Black holes in binary stellar systems - (BH3) Black holes in galactic nuclei |
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Speaker |
Rezzolla, Luciano |
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Coauthors |
A. Abdujabbarov, B. Ahmedov |
| Talk Title |
A coordinate independent characterization of a black-hole shadow |
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Abstract |
A large international effort is under way to assess the presence of a shadow in the radio emission from the compact source at the center of our galaxy, Sag-A*. If detected, this shadow would provide the first evidence of the existence of black holes and that Sag-A* is a supermassive black hole. In addition, the shape of the shadow could be used to learn about extreme gravity near the event horizon and to determine which theory of gravity better describes the observations. The mathematical description of the shadow has so far been done making use of a number of simplifying assumptions that are unlikely to be offered by the real observational data. We here provide a general formalism to describe the shadow as an arbitrary polar curve expressed in terms of a Legendre expansion. Our formalism does not presume any knowledge of the properties of the shadow and offers a number of routes to characterize the properties of the curve and its distortions that can be implemented across different analyzing teams. |
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Talk view |
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