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arXiv · 1301.1396

Method for detecting a boson star at Sgr A* through gravitational lensing

Amitai Y. Bin-Nun
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Abstract

Observations of the Sgr A* region in the galactic center confirm the presence of a large amount of matter in a small volume, leading to the consensus that a black hole exists there. However, dynamical observations cannot rule out the presence of a boson star, a compact object made up of scalar particles, as both objects are far more compact than the scale of current observational constraints. While a boson star in the galactic center is disfavored for a number of theoretical considerations, we outline the first test that can directly observe a boson star. We accomplish this by studying the strong gravitational lensing of S stars resulting from the assumption of a boson star in the Galactic Center. Boson stars have an extended mass distribution and are transparent to electromagnetic radiation, giving rise to a radial caustic curve. We calculate the brightness of images formed by stars crossing these radial caustics and show that a boson star would give rise to much brighter images than a black hole with a similar mass and that those images would be easily bright enough to be detected with upcoming instruments.

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Amitai Y. Bin-Nun. 2013-01-08. Method for detecting a boson star at Sgr A* through gravitational lensing. https://arxiv.org/abs/1301.1396

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