ROSAT Observations of the Two Radio-selected Blazars PKS 1034-293 and PKS 1335-127

ROSAT observations of two blazars are presented. Spectral fits with a single absorbed power law with free n_H_ yield {GAMMA} = 1.23_- 0.50_^+0.54^, n_H_ = 1.3_-1.2_^+1.7^ (10^20^ cm^-2^), for PKS 1034-293 and {GAMMA} = 2.29_-0.51_^+0.55^, n_H_ = 6.60_-2.23_^+3.00^ (10^20^ cm^- 2^), for PKS 1335 - 127, respectively. For the first source, the derived column density is significantly smaller than the Galactic value, suggesting a soft excess. A fit with a broken power law, with n_H_ fixed at the Galactic value, yields a concave spectrum ({GAMMA}_1_ = 4.00_- 1.39_^+15.1^,{GAMMA}_2_ = 1.36_-0.44_^+0.45^). Alternatively, the concavity can be modeled with an absorption edge or notch superposed on a steeper continuum. Reanalysis of the Einstein observations of the two sources, with n_H_ fixed at the value determined by ROSAT, yields a very flat Einstein X-ray slope for PKS 1034 - 293, {GAMMA} = 0.83_- 0.90_^+0.68^, consistent with the ROSAT result, while for PKS 1335 - 127 the Einstein slope, {GAMMA} = 1.36_-0.53_^+0.48^ is flatter than that determined with ROSAT. A comparison of the X-ray spectra with the broadband energy distributions suggests that in both cases a significant contribution from a process other than synchrotron, most likely inverse Compton, is present in the X-ray band.