Cartoon representing the X-ray LCs types. For the X-ray LC shapes we used the code presented in M 13. Following the prescription of Bernardini et al. (2012a) and M 13, we denoted the different parts of the LCs as a) steep decay (S, green): first segment of type Ib and IIa LCs; the second segment of type IIb and III LCs; b) plateau (P, red): the first segment of type Ia LCs; the second segment of type Ib and IIa LCs; the third segment of type IIb and III LCs; c) normal decay (N, blue): type 0 LCs; the second segment of type Ia LCs; the third segment of type IIa LCs; the forth segment of type III LCs.