Probing the Black Hole in the Center of Our Galaxy with Hydrogen Recombination Lines

Elena Murchinkova (Caltech)

The Milky Way's own supermassive black hole Sagittarius A* is our best hope for studying black holes' immediate environments and their growth. Among the wide variety of accretion models, the only thing we know with certainty is that the amount of the material around Sagittarius A* is likely small and its accretion is very low. I describe the first [preliminary] detection of the n=31 -> 30 recombination lines of Hydrogen from within ~0.02pc around the black hole. This line probes the amount and the dynamics of previously unobserved 10^4 K ionized gas, which is the likely accretion reservoir of Sagittarius A*. I will also describe our future observations, which will constrain the amount of neutral hydrogen in the accretion zone using the close flyby of the S2 star by the galactic center in April 2018.

Thursday, 5 October 2017