Context :

Aims : We determine the nature of the intermediate polar candidates XSS~J00564+4548 , IGR~J17195–4100 , and XSS~J12270–4859 .

Methods : Pointed RXTE observations searched for intermediate polar characteristics in these candidate systems .

Results : XSS~J00564+4548 exhibits a period of 465.68 \pm 0.07 s , which we interpret as the spin period , an energy dependent modulation depth , and a spectrum that is fit by a 22 keV photoelectrically absorbed bremsstrahlung with an iron line profile . IGR~J17195–4100 shows several candidate periodicities and a spectrum that is fit by a power law with an iron line . XSS~J12270–4859 exhibits a candidate spin period of 859.57 \pm 0.64 s and a spectrum that is fit by a power law with no evidence of an iron line .

Conclusions : XSS~J00564+4548 is confirmed to be an intermediate polar . IGR~J17195–4100 and XSS~J12270–4859 both show some properties of intermediate polars , but can not be confirmed as definite members of the class here .