The X-ray properties of typical high-redshift radio-loud quasars
  We report spectral, imaging, and variability results from four new XMM-Newton
observations and two new Chandra observations of high-redshift (z > 4)
radio-loud quasars (RLQs). Our targets span lower, and more representative,
values of radio loudness than those of past samples of high-redshift RLQs
studied in the X-ray regime. Our spectral analyses show power-law X-ray
continua with a mean photon index, \Gamma =1.74 +/- 0.11, that is consistent
with measurements of lower redshift RLQs. These continua are likely dominated
by jet-linked X-ray emission, and they follow the expected anti-correlation
between photon index and radio loudness. We find no evidence of iron K\alpha ~
emission lines or Compton-reflection continua. Our data also constrain
intrinsic X-ray absorption in these RLQs. We find evidence for significant
absorption (N_H ~ 10^22 cm^-2) in one RLQ of our sample (SDSS J0011+1446); the
incidence of X-ray absorption in our sample appears plausibly consistent with
that for high-redshift RLQs that have higher values of radio loudness. In the
Chandra observation of PMN J221-2719 we detect apparent extended (~ 14 kpc)
X-ray emission that is most likely due to a jet; the X-ray luminosity of this
putative jet is ~2% that of the core. The analysis of a 4.9 GHz VLA image of
PMN J221-2719 reveals a structure that matches the X-ray extension found in
this source. We also find evidence for long-term (450-460 days) X-ray
variability by 80-100% in two of our targets.
