# Bow shock sources close to the Galactic centre

## TL;DR

This paper reviews observational and theoretical studies of stellar bow-shock sources near the Galactic centre, highlighting how bow-shock data can reveal the motion of stars and the density of the hot accretion flow.

## Contribution

It introduces a statistical method to estimate the ambient density slope using multiple bow-shock observations at different distances from Sgr A*.

## Key findings

- Bow-shock symmetry axis indicates star motion relative to ambient medium.
- Photometry and spectroscopy provide 3D stellar motion information.
- Method to infer ambient density slope from multiple bow-shock detections.

## Abstract

We provide an up-to-date summary of the current observational and theoretical studies of stellar bow-shock sources close to the Galactic centre. The symmetry axis of a bow shock provides the information on the relative motion of the star with respect to the ambient medium, while the photometry and spectroscopy in NIR domain give information about the 3D motion of the star. Hence, it is possible from this data to obtain an estimate on the motion of the ambient medium. In combination with the estimate of the bow-shock size, it is possible to infer the valuable information on the density of the hot accretion flow close to the Galactic centre. In particular, we outline a statistical method to determine the ambient density slope based on either multiple bow-shock detections for one star along its orbit or multiple bow-shock detections for several sources at different distances from Sgr A*.