X-ray echoes revealing Sgr A*'s past activity

XMM-Newton and Chandra observations of the Galactic center taken over the past two decades have been monitoring X-ray echoes propagating in the Central Molecular Zone. This variable non-thermal emission is likely due to outbursts from the supermassive black hole, Sgr A*, that occurred in the last 1000 years. However, the exact description of this recent history has been debated. I will present the latest temporal and spectral analyses which constrain the line-of-sight positions of the molecular clouds reflecting Sgr A*'s radiation towards us. The time delays derived from these measurements prove, with a significance of 5 sigma, the presence of at least two luminous events in the last 300 years.