Constraining the distribution of dark matter at the Galactic centre using the high-resolution Event Horizon Telescope

Abstract

We investigate constraints on the distribution of dark matter in the neighbourhood of the Galactic centre that may eventually be attained with the high-resolution Event Horizon Telescope (EHT). The shadow of a black hole in vacuum is used to generate a toy model describing how dark matter affects the size of the shadow of the supermassive black hole located at the Galactic centre. Observations by the EHT may constrain the properties of the dark matter distribution in a possible density spike around the black hole. Current uncertainties due to both the resolution of the telescope and the analysis of stellar orbits prevent one from discerning the effect of dark matter on the measured size of the shadow. The change in the size of the shadow induced by dark matter can be seen as an additional uncertainty in any test of general relativity that relies on using the angular size of the shadow to estimate the Schwarzschild radius of the black hole.

5 pages, 4 figures. v2: a few comments and references added, one figure replaced for clarity, results unchanged, matches version published in A&A

References in corpus (4)

• The orbit of the star S2 around SgrA* from VLT and Keck data
• Gravitational Lensing by Black Holes
• Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects
• Multi-wavelength signals of dark matter annihilations at the Galactic center

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• Ring-down gravitational waves and lensing observables: How far can a wormhole mimic those of a black hole?
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• Investigating effects of dark matter on photon orbits and black hole shadows
• Silhouettes of invisible black holes
• Strong field lensing by Damour-Solodukhin wormhole
• Event horizon image within black hole shadow
• Constraints via the Event Horizon Telescope for Black Hole Solutions with Dark Matter under the Generalized Uncertainty Principle Minimal Length Scale Effect
• To see invisible: image of the event horizon within the black hole shadow
• Geodesic structure, shadow and optical appearance of black hole immersed in Chaplygin-like dark fluid
• Gravitational Lensing of a star by a rotating black hole
• Event horizon silhouette: implications to supermassive black holes M87* and SgrA*
• Strong lensing by fermionic dark matter in galaxies
• Can massless wormholes mimic a Schwarzschild black hole in the strong field lensing?
• Can accretion properties distinguish between a naked singularity, wormhole and black hole?
• On the Doppler effect for light from orbiting sources in Kerr-type metrics
• Constraining Self-interacting Scalar Field Dark Matter From the Black Hole Shadow of the Event Horizon Telescope
• Accretion of Self-interacting Scalar Field Dark Matter Onto a Reissner-Nordström Black Hole
• Classification of a black hole spin out of its shadow using support vector machines
• Terrestrial Sagnac delay in scalar-tensor-vector-gravity
• Visible shapes of black holes M87* and SgrA*