New Dynamical Channel: Wide Binaries in the Galactic Center as a Source of Binary Interactions

TL;DR

This paper introduces a new dynamical channel in the galactic center where wide binaries, previously overlooked, can interact more frequently due to gravitational perturbations, leading to various astrophysical phenomena.

Contribution

It demonstrates that wide binaries in the galactic center can be a significant source of binary interactions through eccentricity excitation caused by gravitational impulses.

Findings

Tens of thousands of MS-MS interacting binaries predicted.

Potential formation of G2-like objects and associated signatures.

Hundreds of BH-MS interacting binaries expected.

Abstract

The inner $500\rm pc$ in the galactic center is dense with stars and a dynamically hot environment. Here, we focus on wide binaries as a source of tidally or collisional interactions. These binaries were previously ignored as sources of binary interaction because they are too wide to have a close pericenter passage, or they will quickly become unbound (ionized) due to gravitational interactions with passing neighbors. However, we show that wide binaries tend to interact more frequently with neighboring stars due to their larger cross-section for gravitational impulse interactions. These interactions mainly torque the wide system, causing it to change its eccentricity. As a result, the eccentricity might be excited to sufficiently high values, causing the binary to interact at the pericenter. As a proof of concept, we present four channels of such interactions: binary main-sequence (MS), white-dwarf (WD) - MS, black hole - MS, and lastly, WD-WD. During Galaxy's lifetime, we predict tens of thousands of MS-MS interacting binaries that may form G2-like objects later appear younger than their environment. X-ray signatures and, perhaps, supernovae may result from thousands of WD-MS and WD-WD interacting binaries from this channel. Lastly, we predict a few hundred BH-MS interacting binaries at the inner $500$~pc.