tokens: however, and is, therefore, highly dependent on the host galaxy colour, with bluer galaxies having the highest Type Ia SNe rate per unit mass (e.g. Mannucci et al. 2005 ; Mannucci, Della Valle Panagia 2006 ). Type Ia SNe commonly occur in elliptical galaxies, including those with very little recent star formation (e.g. Oemler Tinsley 1979 ; Cappellaro et al. 1999 ; Mannucci et al. 2005 ; Barkhudaryan et al. 2019 ), however, showing at least some progenitors are from older stellar populations. The radial distribution of Type Ia SNe does not correlate with the UV flux distributions at a statistically significant level (see Fig. 4a : p = 0.01 for both NUV and FUV), in agreement with Anderson et al. ( 2015b ). As UV is a useful tracer of moderate- to high-mass stars and, therefore, also a tracer of moderate emission time-scales (e.g. Hygate et al. 2019 ), the divergence of the UV CDF from the dotted normal line in Fig. 4(a) suggests that Type Ia SNe have progenitor systems from different mass and time-scale ranges. 3.2 Type II SNe The radial distribution of Type II SNe shows strong agreement with both UV fluxes ( p = 0.73 and 0.71 for NUV and FUV, respectively) and differs from the R -band and H α light distributions at, or near, statistically significant levels: p = 0.05 and 0.02, respectively (see Fig. 5a and the Appendix). Type II SNe occur throughout the optical disc and examples can be found near or at (see also Figs 6e and f ). Figure 5. CDFs for (a) Type II SNe, (b) stripped-envelope supernova (SE SNe: Types Ib, Ic, Ib/c, and IIb), and (c) the combined Type II and SE SNe sample. See Fig. 4 for further description. Figure 6. Normalized radial flux profiles shown as separate differently coloured lines, with SN locations indicated with small red circle(s): Type Ia SNe (top row), Type II SNe (middle row), and SE SNe (bottom row). The average radial positions for Type Ia, Type II, and SE SNe are marked on each plot using a black cross, circle, and triangle, respectively, and these show the now well-known centralization of SE SNe compared to Type II SNe. To aid comparison, the mean positions of the other SN types are shown with grey symbols. The lack of SE SNe in the outer regions of the UV apertures is evident in panels k, l, with no SE SNe observed in the outer ∼30 per cent of the UV light distribution, compared to the absence of SE SNe in the outer ∼18 per cent of the H α light distribution (panel j). See Sections 3.3.1 and 4.2 for further discussion. The H α CDF for Type II SNe (see Fig. 5a ) has a central section with a reduced slope; just over 10 per cent of Type II SNe are found in 30 per cent of the flux (between 30 and 60 per cent of the total flux – see also Fig. A1b ). Strong bars are known to cause a notable suppression of massive star formation in early-type spirals (see Hakobyan et al. 2016a and references therein) and this could contribute to this CDF feature. No Type II SNe are found in the outer ∼30 per cent of the FUV
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength O O O O O O O O O O O B-Formula I-Formula I-Formula O O B-Wavelength O B-Wavelength O O O B-Citation I-Citation I-Citation I-Citation I-Citation I-Citation O B-Wavelength O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O B-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength O O B-Formula I-Formula I-Formula O O O B-Wavelength O B-Wavelength O O O O O B-Wavelength I-Wavelength O B-Wavelength I-Wavelength O O O O O O O O B-Formula I-Formula I-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength O O O O O O O O O O O O O O O O O O O O B-Wavelength O O O O O O O O O O O O O O O O O B-Wavelength I-Wavelength O O O O O O O O O O O O O B-Wavelength I-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength