Article

Calcium in a supernova remnant as a fingerprint of a sub-Chandrasekhar-mass explosion

Priyam DasHeidelberger Institut für Theoretische Studien, Heidelberg, GermanyI. R. SeitenzahlHeidelberger Institut für Theoretische Studien, Heidelberg, GermanyAshley J. RuiterARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions, Canberra, Australian Capital Territory AustraliaF. K. RöpkeHeidelberger Institut für Theoretische Studien, Heidelberg, GermanyRüdiger PakmorMax-Planck-Institut für Astrophysik, Garching, GermanyF. VogtFederal Office of Meteorology and Climatology - MeteoSwiss, Payerne, SwitzerlandChristine E. CollinsGSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, GermanyParviz GhavamianDepartment of Physics Astronomy and Geosciences, Towson University, Towson, MD USAStuart SimSchool of Mathematics and Physics, Queen's University Belfast, Belfast, UKBrian J. WilliamsX-ray Astrophysics Laboratory, NASA/GSFC, Greenbelt, MD USAS. TaubenbergerMax-Planck-Institute for Astrophysics, Garching, GermanyJ. M. LamingSpace Science Division, Code 7684, Naval Research Laboratory, Washington, DC USAJanette SuherliDepartment of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba CanadaRalph S. SutherlandResearch School of Astronomy and Astrophysics, Australian National University, Weston Creek, Australian Capital Territory AustraliaNicolás Rodríguez-SegoviaSchool of Science, University of New South Wales, Australian Defence Force Academy, Canberra, Australian Capital Territory Australia

2025en

ABI

Abstract

Type Ia supernovae play a fundamental role as cosmological probes of dark energy and produce more than half of the iron in our Galaxy. Despite their central importance, a comprehensive understanding of their progenitor systems and triggering mechanism is still a long-standing fundamental problem. Here we present high-resolution integral field spectroscopic observations of the young supernova remnant SNR 0509-67.5 in the Large Magellanic Cloud. We uncover a double-shell morphology of highly ionized calcium [Ca XV] and a single shell of sulphur [S XII], observed in the reverse shocked ejecta. Our analysis reveals that the outer calcium shell originates from the helium detonation at the base of the outer envelope, while the inner shell is associated with the carbon-oxygen core detonation. This morphological distribution of intermediate-mass elements agrees qualitatively with the predicted signature of the double detonation of a sub-Chandrasekhar-mass white dwarf from a hydrodynamical explosion simulation. Our observations reveal two distinct, spatially separated peaks in surface brightness of [Ca XV] from the supernova remnant phase, providing substantial evidence that sub-Chandrasekhar-mass explosions through the double-detonation mechanism could occur in nature. They also highlight the importance of remnant tomography in understanding explosion mechanisms from the remnant phase.

Identifiers

DOI: 10.1038/s41550-025-02589-5

Citations and references

Cited by 10 references

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