Shadows of Kerr-Vaidya-like black holes

Abstract

In this work, we study the shadow boundary curves of rotating time-dependent black hole solutions which have well-defined Kerr and Vaidya limits. These solutions are constructed by applying the Newman-Janis algorithm to a spherically symmetric seed metric conformal to the Vaidya solution with a mass function that is linear in Eddington-Finkelstein coordinates. Equipped with a conformal Killing vector field, this class of solution exhibits separability of null geodesics, thus allowing one to develop an analytic formula for the boundary curve of its shadow. We find a simple power law describing the dependence of the mean radius and asymmetry factor of the shadow on the accretion rate. Applicability of our model to recent Event Horizon Telescope observations of M87${}^{\ast }$ and Sgr A${}^{\ast }$ is also discussed.

28 pages, 9 figures. [v4]: minor edits

References in corpus (14)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• Black Hole Shadows, Photon Rings, and Lensing Rings
• Calculating black hole shadows: Review of analytical studies
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• The Shadow of a Spherically Accreting Black Hole
• Axion-plasmon or magnetized plasma effect on an observable shadow and gravitational lensing of a Schwarzschild black hole
• Photon sphere and shadow of a time-dependent black hole described by a Vaidya metric
• Space-time diagrammatics
• Testing black hole equatorial reflection symmetry using Sgr A* shadow images

Cited by in corpus (4)

• General Approach on Shadow Radius and Photon Spheres in Asymptotically Flat Spacetimes and the Impact of Mass-Dependent Variations
• Image of the time-dependent black hole
• Aberration effect on lower-order images of thin accretion disk in the astrometric approach
• Analytical approach for calculating shadow of dynamical black hole