On variations of the brightness of type Ia supernovae with the age of the host stellar population

Abstract

Recent observational studies of type Ia supernovae (SNeIa) suggest correlations between the peak brightness of an event and the age of the progenitor stellar population. This trend likely follows from properties of the progenitor white dwarf (WD), such as central density, that follow from properties of the host stellar population. We present a statistically well-controlled, systematic study utilizing a suite of multi-dimensional SNeIa simulations investigating the influence of central density of the progenitor WD on the production of Fe-group material, particularly radioactive Ni-56, which powers the light curve. We find that on average, as the progenitor's central density increases, production of Fe-group material does not change but production of Ni-56 decreases. We attribute this result to a higher rate of neutronization at higher density. The central density of the progenitor is determined by the mass of the WD and the cooling time prior to the onset of mass transfer from the companion, as well as the subsequent accretion heating and neutrino losses. The dependence of this density on cooling time, combined with the result of our central density study, offers an explanation for the observed age-luminosity correlation: a longer cooling time raises the central density at ignition thereby producing less Ni-56 and thus a dimmer event. While our ensemble of results demonstrates a significant trend, we find considerable variation between realizations, indicating the necessity for averaging over an ensemble of simulations to demonstrate a statistically significant result.

5 pages, 4 figures, 1 table, accepted to ApJL

References in corpus (7)

• Improved Distances to Type Ia Supernovae with Multicolor Light Curve Shapes: MLCS2k2
• Consistent estimates of (56)Ni yields for type Ia supernovae
• Capturing the Fire: Flame Energetics and Neutronizaton for Type Ia Supernova Simulations
• Flame Evolution During Type Ia Supernovae and the Deflagration Phase in the Gravitationally Confined Detonation Scenario
• Neutronization During Type Ia Supernova Simmering
• The Reduction of the Electron Abundance during the Pre-explosion Simmering in White Dwarf Supernovae
• Convection during the Late Stages of Simmering in Type Ia Supernovae

Cited by in corpus (12)

• SNLS3: Constraints on Dark Energy Combining the Supernova Legacy Survey Three Year Data with Other Probes
• Evaluating Systematic Dependencies of Type Ia Supernovae: The Influence of Deflagration to Detonation Density
• The white dwarf's carbon fraction as a secondary parameter of Type Ia supernovae
• On the evolution of rotating accreting white dwarfs and type Ia supernovae
• Late-time near-infrared observations of SN 2005df
• Evaluating Systematic Dependencies of Type Ia Supernovae: The Influence of Central Density
• The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
• A supersymmetric model for triggering Supernova Ia in isolated white dwarfs
• Type Ia Supernova Explosions from Hybrid Carbon-Oxygen-Neon White Dwarf Progenitors That Have Mixed During Cooling
• Testing the Constancy of Type Ia Supernova Luminosities with Gaussian Process
• Evaluating Systematic Dependencies of Type Ia Supernovae
• Diversity of Type Ia supernova optical light curves among different spectroscopic subclasses