# Evidence for GR rotational frame-dragging in the light from the Sgr A* supermassive black hole - Astrophysics > Astrophysics of Galaxies

Abstract: The analysis of flare start-times confirms the periods found years agoAschenbach et al., 2004 in the near-infrared and X-ray light-curves relatedto the Sgr A* black hole. The assignment of the frequencies found to radial andvertical epicyclic frequencies $u\sb{ m r}$, $u\sb{ m v}$, respectively,as well as to the Kepler orbital frequency $u\sb{ m K}$ reveals resonancesof $u\sb{ m v}$ - $u\sb{ m r}$=7:2, and $u\sb{ m K}$ - $u\sb{ mv}$=3:1. The highest observed frequency of 10 mHz is identified as the Keplerfrequency corrected by the rotational frame-dragging frequency, as expectedfrom the Lense-Thirring effect. These frequency assignments conclude a blackhole mass of M = 4.10-4.34$\times10\sp{6} M \odot$ and a spin of a =0.99473-0.99561.

Author: Bernd Eduard Aschenbach

Source: https://arxiv.org/