The diversity of type Ia supernovae from broken symmetries

摘要: The near uniformity of the light curves type Ia supernovae makes them good standard candles for measuring cosmic expansion, but an observational correction (whose underlying physics has been unknown) must be applied to account fact that brighter ones have 'broader' curves. Kasen et al. report multi-dimensional modelling explosion and radiative transfer supernovae, which reveals breaking spherical symmetry is a critical factor in determining both width luminosity relation observed scatter about it. slope normalization width–luminosity weak dependence on trace abundances elements other than carbon oxygen. Failing correct this effect could lead systematic overestimates up 2% distance remote supernovae. This work step towards explaining nature supernova events behind their suitability as cosmological probes. 'standard candles' broader Here, radioactive failing Type result when carbon-oxygen white dwarfs binary systems accrete mass from companion stars, reach explode. these ‘standard candles’ expansion1,2,3,4, curves5. One-dimensional modelling, with certain choice parameters, can reproduce general trend relation6,7,8; processes ignition detonation recently shown intrinsically asymmetric9,10,11,12,13, so parameterization its limits. Here we transfer, deviation also explain finite polarization detected some supernovae14. properties dwarf progenitor, particular 2 per cent