Flaring in the Heart of the Milky Way: X-ray and Infrared Variability of Sgr A* from Chandra and Spitzer

Emission from the supermassive black hole at the center of our galaxy, Sagittarius A* (Sgr A*), is variable at both X-ray and infrared (IR) wavelengths. The physical mechanism behind this variability is still unknown, but careful characterization of the emission using simultaneous multi-wavelength observations can constrain models for the accretion flow and the emission. For the X-ray/IR relationship, simultaneous observations have shown that X-ray flares are typically accompanied by a rise in the IR activity, while the opposite is not always true. However, it is not clear whether jointly-detected flares occur with the X-ray or the IR emission "leading" the other by a few minutes, or whether they happen truly simultaneously. Using 100+ hours of overlapping data from a coordinated campaign between the Spitzer Space Telescope and the Chandra X-ray Observatory, we present results of the longest simultaneous IR and X-ray observations of Sgr A* taken to date and report the constraints they give on flare simultaneity. The details of this analysis is reported in Boyce et al. (2019).