The Galactic center black hole Sgr A is known to exhibit regularly flares of radiation, during which Sgr A flux gets brighter by a factor of up to ~10 with respect to the quiescence. The physical origin of these flares is thus far only weakly constrained.
In this talk, I will present a new model for the quiescent state of Sgr A, based on the superimposition of a thick torus and a large-scale jet. This model allows to account for spectral and VLBI data from the radio to the infrared. I will also discuss a model for Sgr A flares based on the trigerring of a Rossby-wave instability in the accretion flow surrounding the black hole. I will discuss how GRAVITY data can help determine what model is correct.
|Choix de session parallèle||1.1 Les diverses facettes du centre galactique : des abords du trou noir à son environnement plus lointain.|