Low-Metallicity Inhibition of Type Ia Supernovae and Galactic and Cosmic Chemical Evolution

Abstract

We introduce a metallicity dependence of Type Ia supernova (SN Ia) rate into the Galactic and cosmic chemical evolution models. In our SN Ia progenitor scenario, the accreting white dwarf (WD) blows a strong wind to reach the Chandrasekhar mass limit. If the iron abundance of the progenitors is as low as [Fe/H] < ∼ − 1, then the wind is too weak for SNe Ia to occur. Our model successfully reproduces the observed chemical evolution in the solar neighborhood. We make the following predictions which can test this metallicity effect: 1) SNe Ia are not found in the low-iron abundance environments such as dwarf galaxies and the outskirts of spirals. 2) The cosmic SN Ia rate drops at z ∼ 1 − 2 due to the low-iron abundance, which can be observed with the Next Generation Space Telescope. At z > ∼ 1 − 2, SNe Ia can be found only in the environments where the timescale of metal enrichment is sufficiently short as in starburst galaxies and ellipticals.The low-metallicity inhibition of SNe Ia can shed new light on the following issues: 1) The limited metallicity range of the SN Ia progenitors would imply that "evolution effects" are relatively small for the use of high redshift SNe Ia to determine the cosmological parameters. 2) WDs of halo populations are poor producers of SNe Ia, so that the WD contribution to the halo mass is not constrained from the iron abundance in the halo. 3) The abundance patterns of globular clusters and field stars in the Galactic halo lack of SN Ia signatures in spite of their age difference of several Gyrs, which can be explained by the low-metallicity inhibition of SNe Ia. 4) It could also explain why the SN Ia contamination is not seen in the damped Lyα systems for over a wide range of redshift.

The effects of AGN feedback on present-day galaxy properties in cosmological simulations

“…The progenitor model of Type Ia supernovae (SNe Ia) is very important for predicting [α/Fe] of galaxies because SNe Ia produce more iron than α elements (O, Mg, Si, S, and Ca). Our SN Ia model is based on the single degenerate scenario with the metallicity effects of white dwarf winds (Kobayashi et al 1998(Kobayashi et al , 2000, and the lifetime distribution functions are calculated as in Kobayashi & Nomoto (2009). These provide an excellent agreement with the observed elemental abundances in the solar neighbourhood (Kobayashi & Nakasato 2011).…”

SYSTEMATIC NON-LTE STUDY OF THE −2.6 ≤ [Fe/H] ≤ 0.2 F AND G DWARFS IN THE SOLAR NEIGHBORHOOD. II. ABUNDANCE PATTERNS FROM Li TO Eu*

“…We will mainly discuss the models of K11 (Kobayashi et al 2011b) and its updated version, K15. Their main features include slow infall, no outflow, star formation proportional to gas fraction, the Kroupa (2001) initial mass function (IMF) at 0.01-50 M e , and the SN Ia model based on the single-degenerate scenario (Kobayashi & Nomoto 2009) with the metallicity effect (Kobayashi et al 1998). The metallicity-dependent nucleosynthesis yields are taken from Kobayashi et al (2006, hereafter K06) and Kobayashi et al (2011b) for SNe and hypernovae (with a 0.5 fraction of hypernovae at 20 M e ), and from Karakas (2010) for AGB stars.…”

“…From [Fe/H] ∼ −1, [C/Fe] decreases due to the delayed enrichment of SNe Ia. Although the lifetimes of these AGB stars (0.15-0.2 Gyr) are comparable to the shortest lifetimes of SNe Ia, the SN Ia contribution appears after the AGB contribution because of the metallicity dependence of the SN Ia lifetimes (Kobayashi et al 1998;Kobayashi & Nomoto 2009). These trends are characteristic of K11 and K15 models and are in excellent agreement with our observational data at [Fe/H]  −1.5.…”

The origin and evolution of the odd-Z iron-peak elements Sc, V, Mn, and Co in the Milky Way stellar disk

“…In addition, models of yields do not always agree with observations because of the scarse knowledge of certain processes in stellar evolution but also because the production of elements in supernovae explosions are highly sensitive to explosion parameters Kobayashi & Nakasato 2011). Another factor is that the presence of any dependence with the metallicity of the SNIa progenitors or the rate of occurrence of SNIa are unclear (Kobayashi et al 1998). In addition, chemodynamical models for certain elements do not always agree with observations.…”