METALLICITY AS A SOURCE OF DISPERSION IN THE SNIa BOLOMETRIC LIGHT CURVE LUMINOSITY-WIDTH RELATIONSHIP

Journal Article · Wed Mar 10 00:00:00 EST 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/711/2/L66; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21305117

Bravo, E ^[1]; DomInguez, I ^[2]; Badenes, C ^[3]; Piersanti, L

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1. Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Carrer Comte d'Urgell 187, 08036 Barcelona (Spain)
2. Departamento de Fisica Teorica y del Cosmos, Universidad de Granada, 18071 Granada (Spain)
3. Benoziyo Center for Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel)

The recognition that the metallicity of Type Ia supernova (SNIa) progenitors might bias their use for cosmological applications has led to an increasing interest in its role in shaping SNIa light curves. We explore the sensitivity of the synthesized mass of {sup 56}Ni, M({sup 56}Ni), to the progenitor metallicity starting from pre-main-sequence models with masses M {sub 0} = 2-7 M {sub sun} and metallicities Z = 10{sup -5}-0.10. The interplay between convective mixing and carbon burning during the simmering phase eventually raises the neutron excess, {eta}, and leads to a smaller {sup 56}Ni yield, but does not change substantially the dependence of M({sup 56}Ni) on Z. Uncertain attributes of the progenitor white dwarf, like the central density, have a minor effect on M({sup 56}Ni). Our main results are: (1) a sizeable amount of {sup 56}Ni is synthesized during incomplete Si-burning, which leads to a stronger dependence of M({sup 56}Ni) on Z than obtained by assuming that {sup 56}Ni is produced in material that burns fully to nuclear statistical equilibrium; (2) in one-dimensional delayed detonation simulations a composition dependence of the deflagration-to-detonation transition (DDT) density gives a nonlinear relationship between M({sup 56}Ni) and Z and predicts a luminosity larger than previously thought at low metallicities (however, the progenitor metallicity alone cannot explain the whole observational scatter of SNIa luminosities); and (3) an accurate measurement of the slope of the Hubble residuals versus metallicity for a large enough data set of SNIa might give clues to the physics of DDT in thermonuclear explosions.

• OSTI ID: 21305117
• Journal Information: Astrophysical Journal Letters, Vol. 711, Issue 2; Other Information: DOI: 10.1088/2041-8205/711/2/L66; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ABUNDANCE
BOLOMETERS
CARBON BURNING
LUMINOSITY
MASS
NICKEL 56
NONLINEAR PROBLEMS
NUCLEAR REACTIONS
NUCLEOSYNTHESIS
SIMULATION
STAR EVOLUTION
SUPERNOVAE
THERMONUCLEAR EXPLOSIONS
WHITE DWARF STARS