  We re-analyze the Chandra ACIS spectrum of the kpc-scale jet in PKS 0637-752
to investigate the possible low energy cutoff in the relativistic electron
spectrum producing the non-thermal radiation in the scenario of inverse Compton
emission off the cosmic microwave background. This was among the first objects
targeted by the Chandra Observatory and gives a unique opportunity to study the
low energy X-ray emission free of detector contamination. As previously
reported in the literature, the spectrum can be fit by a power law, with the
slope predicted by the radio spectrum, modified by low energy absorption
through the Galaxy as determined from the spectrum of the quasar core and by HI
21 cm observations. We obtain a marginally better fit with an model of inverse
Compton emission produced by an electron population that exhibits a cutoff at
(gamma_min delta_10) between about 50 and 80 (assuming Gamma = delta). This
range for gamma_min is higher than has previously been assumed in broad-band
spectral fits to the jet emission. The observed optical flux can be used to
place a lower limit on gamma_min; the constraint is not very strong, but does
suggest that gamma_min must be higher than 1 to avoid overproducing the optical
emission. We investigate the effect of uncertainties in the column density for
galactic absorption as well as the calibration of Chandra for these early
observations. Finally, we discuss the implication of these limits on the jet
luminosity in this source.
