Spatial distributions of core-collapse supernovae in infrared-bright galaxies

We have measured the correlation between the locations of core-collapse supernovae (CCSNe) and host galaxy light in the H alpha line, near ultraviolet (NUV), R band and Ks band to constrain the progenitors of CCSNe using pixel statistics. Our sample consists of 86 CCSNe in 57 infrared (IR)-bright galaxies, of which many are starbursts and 10 are luminous infrared galaxies (LIRGs). We also analyse the radial distribution of CCSNe in these galaxies, and determine power-law and exponential fits to CCSN surface density profiles. To probe differences between the SN population of these galaxies and normal spiral galaxies, our results were compared to previous similar studies with samples dominated by normal spiral galaxies where possible. We obtained a normalized scale length of 0.23(-0.02)(+0.03) R-25 for the surface density of CCSNe in IR-bright galaxies; less than that derived for CCSNe in a galaxy sample dominated by normal spiral galaxies (0.29 +/- 0.01). This reflects a more centrally concentrated population of massive stars in IR-bright galaxies. Furthermore, this centralization is dominated by a central excess of Type Ibc/IIb SNe. This may be due to a top-heavy initial mass function and/or an enhanced close binary fraction in regions of enhanced star formation. Type Ic SNe are most strongly correlated with H alpha light and NUV-bright regions, reflecting the shortest lifetime and thus highest mass for Type Ic progenitors. Previous studies with samples dominated by normal spiral galaxies have indicated a lower Ibc-H alpha correlation than our results do, which may be due to the central excess of Type Ibc/IIb SNe in our sample. The difference between Types II and Ib is insignificant, suggesting that progenitor mass is not the dominant factor in determining if a SN is of Type Ib or II. Similar differences in correlation can be seen in the Ks band (which in these galaxies is dominated by red supergiants and thus also traces recent star formation), with Type Ibc/IIb SNe tracing the Ks-band light better than Type II in our sample.