Radioactively-Powered Rising Lightcurves of Type Ia Supernovae

摘要: The rising luminosity of the recent, nearby supernova 2011fe shows a quadratic dependencewith time during the first ≈ 0.5-4 days. In addition, composite lightcurves formed from stacking together many Type Ia supernovae (SNe Ia) show similar power-law index 1.8±0.2 with time. I explore what range power-law rises are possible due to presence radioactive material near surface exploding white dwarf (WD). summarize constraints such model places on structure progenitor and distribution and velocity ejecta. My main conclusion is that rise SN requires mass fraction X_(56) 3×10^(-2) of ^(56)Ni (or some other heating source like ^(48)Cr) distributed between depth 4×10^(-3) -0.1M_⊙ below the WD’s surface. Radioactive elements this shallow not found in simulations single C/O detonation. Scenarios may produce include helium-shell burning during double-detonation ignition, a gravitationally confined detonation, subset deflagration detonation transition models. general, the power-law can differ depending details event, so comparisons work with observed bolometric rises SNe Ia would place strong distribution radioactive material, providing important clues for identifying elusive progenitors Ia.