We present the results of Chandra ACIS-S snapshot observations of six radio-loud quasars ( RLQs ) at z \approx 3.5–4.7 .
These observations sample luminous RLQs with moderate-to-high radio-loudness ( R \approx 200–9600 ) and aim to connect the X-ray properties of radio-quiet quasars ( R < 10 ) and highly radio-loud blazars ( R > 1000 ) at high redshift .
This work extends a study by Bassett et al .
( 2004 ) which used similar methods to examine z > 4 RLQs with moderate radio-loudness ( R \approx 40–400 ) .
All of our targets are clearly detected .
A search for extended X-ray emission associated with kpc-scale radio jets revealed only limited evidence for X-ray extension in our sample : three sources showed no evidence of X-ray extension , and the other three had 3–30 % of their total X-ray fluxes extended > 1 ^ { \prime \prime } away from their X-ray cores .
Additionally , we do not observe any systematic flattening of the optical-to-X-ray spectral index ( \alpha _ { ox } ) compared to low-redshift quasars .
These results suggest that kpc-scale X-ray jet emission is not dominated by inverse-Compton scattering of CMB-seed photons off jet electrons .
We measured X-ray continuum shapes and performed individual and joint spectral fits of our data combined with eight archival RLQs .
A single power-law model acceptably fit the data , with best-fit photon indices of 1.72 ^ { +0.11 } _ { -0.12 } for moderate- R sources and 1.47 ^ { +0.13 } _ { -0.12 } for high- R sources .
We added an intrinsic absorption component to our model , and neither the moderate- R nor the high- R fits set a lower bound on N _ { H } .
The upper limits were N _ { H } < 3.0 \times 10 ^ { 22 } cm ^ { -2 } and N _ { H } < 2.8 \times 10 ^ { 22 } cm ^ { -2 } , respectively .
Our spectral results suggest that intrinsic absorption does not strongly depend on radio-loudness , and high- R sources have flatter power laws than moderate- R sources .
Overall , our high-redshift RLQs have basic X-ray properties consistent with similar RLQs in the local universe .