Thus, to avoid biasing the current sample against or in favour of one of the SN types, we truncate the sample to distances ${\leq {\rm 100~Mpc}}$.

In addition, following the approach described in detail in Paper , we classify the morphological disturbances of the host galaxies from the visible signs of galaxy–galaxy interactions in the SDSS DR10. We adopted the following categories for SN host disturbances: normal (hosts without any visible disturbance in their morphological structure), perturbed (hosts with visible morphological disturbance, but without long tidal arms, bridges, or destructed spiral patterns), interacting (hosts with obvious signs of galaxy–galaxy interaction), merging (hosts with ongoing merging process), and post-merging/remnant (single galaxies that exhibit signs of a past interaction, with a strong or relaxed disturbance). Here, we make use of this classification in order to exclude from the present analysis any host galaxy exhibiting strong disturbances (interacting, merging, and post-merging/remnant).

3.5pt \[table\_SN\_morph\]

  ------ --- ---- --- ---- ---- ---- ----- ---- ---- ---- --- -----
                                                              
                                                              
  Ia       1    9   5    8   13   13    13    6   12    3   0    83
  Ib       0    0   0    0    1    5     3    0    1    2   1    13
  Ib/c     0    0   0    0    0    2     0    0    0    0   