Runaway stars and the Galactic supernova remnant landscape: non-thermal emission and observational evidence

Abstract

Context. A significant fraction (~30%) of massive stars in our Galaxy are moving supersonically through the interstellar medium, which strongly governs their location at the time they end their lives, e.g. die as a supernova and give birth to a supernova remnant (SNR). These dead stellar environments accelerate particles, emitting by non-thermal mechanisms up to the TeV range, and they are considered as a major contributor to the very-high-energy band of the local cosmic-ray spectrum. Aims. This study investigates the effect of the runaway motion of supernova progenitors on the spatial distribution of SNRs in the Milky Way and how this influences the deduced properties of the population. Methods. We construct Galactic populations of SNRs by Monte Carlo simulation, taking into account the bulk motion and the evolution history of their progenitor stars once ejected from their parent clusters. The gamma-ray domain emission of each population is then calculated, to be compared with the High Energy Stereoscopic System (H.E.S.S.) Galactic Plane Survey. Results. We find that including the runaway motion of supernova progenitors strongly modifies the detectability of the simulated emission of their remnants in the very-high-energy band. Particularly, our best fit model using a Reid Milky Way model for core-collapse supernova progenitors requires 33% of massive runaway stars, which is close to the known fraction of runaway high-mass stars, to be in accordance with the H.E.S.S. Galactic Plane Survey data. Conclusions. Our results show that the runaway nature of supernova progenitors must be taken into account in the study of the Galactic population of SNRs within the H.E.S.S. Galactic Plane Survey and the forthcoming Galactic Plane Survey of the Cherenkov Telescope Array Observatory, as it is a governing factor of the detectability of non-thermal emission of their subsequent SNRs.

arXiv commentAccepted (14.08.2025) for publication in A&A. 6 pages. 4 figures

References in corpus (24)

• On the variation of the Initial Mass Function
• Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• The H.E.S.S. Galactic plane survey
• Parametrization of gamma-ray production cross-sections for pp interactions in a broad proton energy range from the kinematic threshold to PeV energies
• Rates and Delay Times of Type Ia Supernovae
• On the spectrum of high-energy cosmic rays produced by supernova remnants in the presence of strong cosmic-ray streaming instability and wave dissipation
• Simple analytical approximations for treatment of inverse Compton scattering of relativistic electrons in the black-body radiation field
• Limits on diffusive shock acceleration in supernova remnants in the presence of cosmic-ray streaming instability and wave dissipation
• The origin of runaway stars
• The Physics of Star Cluster Formation and Evolution
• Very massive runaway stars from three-body encounters
• Distances, Radial Distribution and Total Number of Galactic Supernova Remnants
• Acceleration of cosmic rays and gamma-ray emission from supernova remnants in the Galaxy
• Runaway Stars, Hypervelocity Stars, and Radial Velocity Surveys
• Galactic runaway O and Be stars found using Gaia DR3
• Progenitor Mass Distribution of Core-Collapse Supernova Remnants in Our Galaxy and Magellanic Clouds based on Elemental Abundances
• Modelling the Galactic very-high-energy $\gamma$-ray source population
• Dynamical evolution of star-forming regions: III. Unbound stars and predictions for Gaia
• Expectation on Observation of Supernova Remnants with the LHAASO Project
• Mixing of materials in magnetised core-collapse supernova remnants
• Prospects for a survey of the Galactic plane with the Cherenkov Telescope Array
• Gamma rays from reaccelerated particles at supernova remnant shocks
• The population of Galactic supernova remnants in the TeV range