Abstract

Contributed Talk - Splinter StellarEndpoints

Friday, 11 September 2026, 14:03   (MW-2235)

Simulations of Elongated Supernova Remnants

Katarzyna Nowak, Manami Sasaki, Martin G. H. Krause, Martin Mayer, Federico Zangrandi
Dr. Karl Remeis Observatory, Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg; Centre for Astrophysics Research, Department of Physics, Astronomy and Mathematics, University of Hertfordshire

Recently, individual supernova remnants with highly elongated morphologies have been reported from XMM-Newton and eROSITA X-ray observations. These remnants exhibit strong X-ray emission predominantly in the 0.7–1.1 keV band, suggesting that the dominant emission arises from iron-rich ejecta. Such characteristics are consistent with Type Ia progenitors, though core-collapse events may also produce asymmetric structures. Understanding the physical origin of elongated supernova remnants requires connecting remnant morphology to asymmetries in the explosion and the surrounding circumstellar medium. Type Ia explosions can develop asymmetries through mechanisms such as gravitationally confined detonation and double detonation, which naturally produce off-centre or collimated ejecta. The interaction of these asymmetric ejecta with the surrounding medium can further shape the remnant, with dense or high-pressure regions channelling the material into elongated structures. In this talk, I present results from two-dimensional hydrodynamic simulations of asymmetric explosions expanding into a uniform circumstellar medium. We explore how the ejecta morphology depends on the explosion geometry, specifically varying the half-opening angle of the explosion. The simulations show that velocity shear within the ejecta leads to adiabatic stretching, producing collimated, elongated structures, while the surrounding shocked medium maintains higher pressure that can compress and guide the ejecta along preferred directions. Over time, this results in remnants with highly elongated morphologies. Synthetic X-ray surface brightness maps derived from these simulations show enhanced elongation in the 0.7–1.1 keV band, highlighting the iron-rich emission. These results are broadly consistent with observations and provide supporting evidence for the connection between explosion asymmetries and the morphology of elongated supernova remnants.