NuSTAR detection of high-energy X-ray emission and rapid variability from Sagittarius A* flares

Understand

Sagittarius A* harbors the supermassive black hole that lies at the dynamical center of our Galaxy.

• Sagittarius A* spends most of its time in a low luminosity emission state but flares frequently in the infrared and X-ray, increasing up to a few hundred fold in brightness for up to a few hours at a time.
• The physical processes giving rise to the X-ray flares are uncertain.
• Here we report the detection with the NuSTAR observatory in Summer and Fall 2012 of four low to medium amplitude X-ray flares to energies up to 79 keV.