The association of supernovae of the four major types (Ia, Ib, II, and II pec) with regions of recent star formation in their parent late-type galaxies is established. The purpose is to place constraints on the possible progenitor populations. This was accomplished through a quantitative analysis of both photographic and CCD Hα images of the galaxies. The CCD images of several parent galaxies were specifically obtained for this dissertation. The geometries of detected giant H II regions on these images near the supernovae sites are determined and compared to the H II region-supernova separation, in order to establish physical association. The specific problems of supernova classification and positional uncertainties, as well as the probability of chance superposition, are considered in this work. In addition, calibrated surface brightness profiles and integrated physical properties are presented for the associated H II regions. For the supernova sites imaged with CCDs, broad-band B images were also obtained, in order to map the distribution of blue stellar populations in the supernovae environments. The results of this study are: (1) from the lack of association with H II regions or bright OB associations, Type Ia supernovae are not likely to be associated with a young massive population, with mass M >=q 8 Modot (which supports the currently-popular model of an evolved binary system involving critical mass transfer on a white dwarf); (2) Type Ib, II, and II pec supernovae, however, are very likely to be associated with massive stellar populations, as theoretically expected; and, (3) the very massive Wolf-Rayet star progenitor model for Type Ib supernovae is not strongly supported here.
- Pub Date:
- Physics: Astronomy and Astrophysics