Modelling multi-wavelength observational characteristics of bow shocks from runaway early type stars

TL;DR

This study models the multi-wavelength observational features of bow shocks around runaway early type stars, revealing how instabilities and temperature gradients influence emissions across infrared, H alpha, and radio wavelengths.

Contribution

It combines hydrodynamical modeling, radiative transfer, and synthetic imaging to analyze the observable properties of bow shocks, highlighting the role of instabilities and temperature gradients.

Findings

Dense knots from instabilities dominate IR, H alpha, and radio emissions.

Large-scale bow shock morphology is consistent across resolutions.

Infra-red intensity slices reveal temperature gradients at 1 kpc distance.

Abstract

We assess the multi-wavelength observable properties of the bow shock around a runaway early type star using a combination of hydrodynamical modelling, radiative transfer calculations and synthetic imaging. Instabilities associated with the forward shock produce dense knots of material which are warm, ionised and contain dust. These knots of material are responsible for the majority of emission at far infra-red, H alpha and radio wavelengths. The large scale bow shock morphology is very similar and differences are primarily due to variations in the assumed spatial resolution. However infra-red intensity slices (at 22 microns and 12 microns) show that the effects of a temperature gradient can be resolved at a realistic spatial resolution for an object at a distance of 1 kpc.