Evolution of 3-9 M☉ Stars for Z = 0.001-0.03 and Metallicity Effects on Type Ia Supernovae

摘要: Recent observations have revealed that Type Ia supernovae (SNe Ia) are not perfect standard candles; they show variations in their absolute magnitudes, light-curve shapes, and spectra. The C/O ratio the SNe progenitors (C-O white dwarfs) may be related to this variation. In work, we systematically investigate effects of stellar mass (M) metallicity (Z) on its distribution C-O dwarfs by calculating evolution from main sequence through end second dredge-up for M=3-9 M? Z=0.001-0.03. We find total carbon fraction just before SN explosion varies range 0.36-0.5. also calculate dependence main-sequence progenitor dwarfs. Our results maximum form decreases significantly toward lower metallicity, number underestimated if effect is neglected. discuss implications these variation Ia, determination cosmological parameters, luminosity function dwarfs, galactic chemical evolution.