Study of the spectral soft excess in high luminosity transient pulsars

The spectra of many X-ray pulsars show a low-energy component in addition to the main power-law, which can be described with different models (both thermal and non-thermal). The study of this feature is essential in order to cast light on the physical processes on-going in accreting sources. Due to the low absorption in its direction, the transient pulsars in the SMC, which can reach high luminosities (Lx > 1E38 erg/s), can provide high statistic spectra at low energies; two of them (XTE J0111-7317 and RX J0059.2-7138) have already shown a clear excess during their outburst. Therefore we ask to perform a triggered observation with XMM of a selected sample of transient pulsars in the SMC, if they undergo a bright outburst, in order to characterize the spectral and timing properties of the soft excess.