Imaging a boson star at the Galactic center

By F. Vincent, Z. Meliani, P. Grandclément, E. Gourgoulhon, O. Straub. 2015

145 citations recorded by the source corpus.

Millimeter very long baseline interferometry will soon produce accurate images of the closest surroundings of the supermassive compact object at the center of the Galaxy, Sgr A*. These images may reveal the existence of a central faint region, the so-called shadow, which is often interpreted as the observable consequence of the event horizon of a black hole. In this paper, we compute images of an accretion torus around Sgr A* assuming this compact object is a boson star, i.e. an alternative to black holes within general relativity, with no event horizon and no hard surface. We show that very relativistic rotating boson stars produce images extremely similar to Kerr black holes, showing in particular shadow-like and photon-ring-like structures. This result highlights the extreme difficulty of unambiguously telling the existence of an event horizon from strong-field images.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/c0fb1240279c7a43de17184fc9fcc044e89384d2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole (2018, background): “The most conservative explanation for Sgr A* is that it is an MBH, assuming that GR is applicable (Genzel et al. 2010; Falcke & Markoff 2013; Vincent et al. 2016).”
Superradiance (2015, background): “The former includes EM counterparts of accretion and two-body processes [708, 709, 710], mostly in the X-ray and radio band (including the recently observed shadow of the supermassive BH candidate in M87 [144, 711, 712]).”
The imitation game: Proca stars that can mimic the Schwarzschild shadow (2021, background): “If the source of light in the vicinity of the BS has the same morphology as it would have around a BH, the lensing of light, and in particular a similar central depression of the emission (the shadow [49]) would also be present [33, 40].”
Calculating black hole shadows: Review of analytical studies (2021, background): “It was argued by Vincent et al [155] that also Boson stars are quite good black-hole impostors, or black-hole mimickers.”
Dynamical boson stars (2012, background): “[467] expresses a number of interesting caveats, and this study is also discussed as part of a more wide ranging paper about efforts to firmly establish Sgr A* as a BH [181].”