Sgr A* Companion S0-2: A Probe of Very High-Mass Star Formation

Abstract

The star S0-2, which is orbiting Sgr A* with a 15-yr period, almost certainly did not form in situ. We propose that it was injected into this close orbit by the tidal disruption of a massive-star binary, whose primary was more massive than S0-2 and at least 60 Msun. From numerical integrations we find that 1-2% of incoming binaries with closest approach equal to 130 AU leave the secondary in an orbit with eccentricity within 0.01 of that of SO-2. If additional stars are found orbiting Sgr A* with relatively short periods, they could be used to probe the formation of massive stars in the Galactocentric region, even though the massive stars themselves have long since perished.

Submitted to ApJ, 12 pages including 2 figures