Accreting white dwarf models of Type I supernovae. III - Carbon deflagration supernovae

Hot Stars: Old-Fashioned or Trendy?

“…Reinecke et al 1999) with the calculations of light curves and synthetic spectra of SN Ia. In a first step, however, this is done by using the standard hydrodynamical model W7 by Nomoto et al 1984. Figure 16 exemplifies the status quo of the synthetic Spectra of Type Ia Supernovae at early phases obtained from this first step, compared to observations.…”

Nucleosynthesis in Supernovae, Hypernovae/Gamma-ray Bursts and Compact Binary Mergers

“…For a while the Chandrasekhar mass models (single degenerates), causing growth towards the Chandrasekhar mass and then central ignition, leading initially to deflagration, possibly changing into a detonation in the outer layers, was the favorite case (see e.g. the W7 model by Nomoto and collaborators [52]). But in the meantime the spectrum of scenarios has widened a lot, involving singledegenerates with off-center ignition and double detonations via He-accretion (see the contribution by Ken Shen to this conference), as well as double degenerate mergers and even WD collisions, which might be all responsible for the observational diversity with multiple subclasses from recent extended surveys.…”

“…Although there has been further progress since then, the review by Hillebrandt et al [21] gives an enlightening overview over all these options. The Mn/Fe ratio as a function of metallicity seems to be a sensitive measure whether near Chandrasekhar mass singledegenerate models (deflagrations like W7 [52] or delayed detonations [24,63]) occur at all, because only they show low Y e -regions close to the center of the WD. Mn comes in form of its only stable isotope 55 Mn, and is the decay product of 55 Co, produced in incomplete and complete Si-burning under optimal conditions with Y e = Z/A = 0.491.…”

The origin and abundances of the chemical elements revisited

“…much of the cosmic ray spallation comes from lower energy particles than those directly detected at earth) are probably such that neither serious disagreement or complete confirmation can be claimed for any of them. Table 6 shows the amounts of elements from carbon to copper produced by a Nomoto et al (1984;Thielemann et al 1986) Type Ia supernova and a Woosley et al (1988) Type II. The former ejected 1.32 solar masses of heavy elements, the latter (which is a 20 Mo star model for SN 1987A) 2.67 Mo of heavy elements.…”

“…On that assumption, Table 6. Chemical composition of supernova ejecta Element SN Ia SN II (Nomoto et al 1984) the Type I's would clearly dominate not only iron production (this used to be taken as an argument against certain kinds of SN I models) but also Si, S, Ar, Ca, V, Cr, Mn, Co, and Ni. Opinion on the rates has changed, and SN II's are now supposed to outnumber SN I's by two or three to one (van den Bergh et al 1987;van den Bergh 1990) even at the present time, and considerably more so in the past (Matteucci and Tornambe 1988).…”