Type II supemovae

Assuming the star formation rate for the Galaxy given in Table 7.9 and that all stars between 10 and 100 M explode as Type II supemovae, estimate the corresponding supernova rates for the IMFs in Table 7.8. How much difference does it make if the upper mass limit for SN is 50 M (The observed rate for SN II in galaxies like our own is of the order of 2 to 3 per century.)... 

Rauscher T, Heger A, Hoffman RD, Woosley SE (2002) Nucleosynthesis in massive stars with improved nuclear and stellar physics. Astrophys J 576 323-348 Rayet M (1995) The p-process in type II supemovae. Astron Astrophys 298 517-532 Rayet M, Prantzos N, Amould M (1990) The p-process revisited. Astron Astrophys 227 271-281 Reedy RC, Arnold JR, Lai D (1983) Cosmic-ray record in solar system matter. Science 219 127-135 Rehkamper M, Halliday AN (1999) The precise measurement of T1 isotopic compositions by MC-ICPMS application to the analysis of geological materials and meteorites. Geochim Cosmochim Acta 63 935-944... 

In this chapter, we will review the characteristics of thermonuclear processing in the three environments we have identified (i) intermediate-mass stars (ii) massive stars and type II supemovae and (iii) type la supemovae. This will be followed by a brief discussion of galactic chemical evolution, which illustrates how the contributions from each of these environments are first introduced into the interstellar media of galaxies. Reviews of nucleosynthesis processes include those by Arnett (1995), Trimble (1975), Truran (1984), Wallerstein et al. (1997), and Woosley et al. (2002). An overview of galactic chemical evolution is presented by Tinsley (1980). 

Nomoto K., Hashimoto M., Tsujimoto T., Thielemann F.-K., Kishimoto N., Kubo Y., and Nakasato N. (1997) Nucleosynthesis in type II supemovae. Nucl. Phys. 616A, 79c-91c. 

In discussing supemovae, one frequently encounters the terms Type la, Ib, and Ic and Type II supemovae. These are spectroscopic classifications. Type I supemovae do not have hydrogen in their spectra, while Type II do. The subclassification of Type I supemovae denotes whether they have silicon or helium in their spectra. Type la supemovae do not have hydrogen or helixim in their spectra but do have silicon. Type Ib supemovae do not have hydrogen or silicon in their spectra, but do have helium. Type Ic s show no hydrogen, helium, or silicon in their spectra. The connection to core-collapse or thermonuclear supemovae discussed above is that Type la supemovae are probably thermonuclear explosions of white dwarf stars. Type II supemovae are probably core-collapse explosions of massive stars. Type Ib and Ic supernova are probably also core-collapse explosions but of massive stars that have lost... 

We have concentrated in this review on three broad categories of stellar and supernova nucleosynthesis sites (i) the mass range 1 M/M 10 of intermediate -mass stars, for which substantial element production occurs during the AGB phase of their evolution (ii) the mass range M lOM , corresponding to the massive star progenitors of type II ( core collapse ) supernovae and (hi) type la supemovae, which are understood to arise as a consequence of the evolution of intermediate mass stars in close binary systems. 

The endpoint in the evolution of stars with more than 8 solar masses is a type II supernova. One should not confuse novae with supemovae and even the two types (i.e., type I and type II) of supemovae are quite different. It will become evident in the following that the sites of these explosive events are only loosely related, despite the similarity in the name. There is a major difference in the underlying mechanism between type I (SN I) and type II supernovae (SNII). The confusing choice of names is, once again, historical. Astronomy is guided by observations... 

Figure 1. Schematic B magnitude light curves are presented for supemovae of Type la, lb, II linear, and II plateau in contrast with that of SN 1987A. The absolute magnitude of SN 1987A is relatively well Known. The displacement with respect to the other types assumes a distance scale corresponding to Ho = 50 km/s/Mpc.

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