A stream of hypervelocity stars from the Galactic Center

TL;DR

This paper predicts a stream of hypervelocity stars originating from the Galactic Center, using N-body simulations to understand their distribution and origin related to binary disruptions by the supermassive black hole.

Contribution

It introduces a model linking the hypervelocity star S5-HVS1 to a larger stellar stream resulting from binary disruptions near the Galactic Center.

Findings

S5-HVS1 is part of a larger stellar stream.

Predicted spatial and velocity distribution of hypervelocity stars.

Binary disruptions explain the origin of hypervelocity stars.

Abstract

Recent observations have found a 1700 km/s star [S5-HVS1] that was ejected from the Galactic Center approximately five million years ago. This star was likely produced by tidal disruption of a binary. In particular, the Galactic Center contains a few million year old stellar disk that could excite binaries to nearly radial orbits via a secular gravitational instability. Such binaries would be disrupted by the central supermassive black hole, and would also explain the observed cluster of B stars ~0.01 pc from the Galactic Center. In this paper we predict S5-HVS1 is part of a larger stream, and use observationally motivated N-body simulations to predict its spatial and velocity distribution.