Shastri, P.Wilkes, BelindaElvis, MartinMcDowell, Jonathan2017-06-081993Shastri, P., B. J. Wilkes, M. Elvis, and J. McDowell. 1993. “Quasar X-Ray Spectra Revisited.” The Astrophysical Journal 410 (June): 29. doi:10.1086/172721.0004-637Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:32955264A sample of 45 quasars observed by the IPC on the Einstein satellite is used to re-examine the relationship between the soft (0.2-3.5 keV) X-ray energy index and radio-loudness. We find that, (1) the tendency for radio-loud quasars to have systematically flatter X-ray slopes than radio-quiet quasars is confirmed with the soft X-ray excess having negligible effect; (2) there is a tendency for the flatness of the X-ray slope to correlate with radio core-dominance for radio-loud quasars, suggesting that a component of the X-ray emission is relativistically beamed; (3) for the RQQs the soft X-ray slopes, with a mean of ,_ 1.0, are consistent with the slopes found at higher energies (2-10 keV) although steeper than those observed for Seyfert 1 galaxies (also 2-10 keV) where the reflection model gives a good fit to the data; (4) the correlation of FeII emission line strength with X-ray energy index is confirmed for radio-quiet quasars using a subset of 18 quasars. The radio-loud quasars show no evidence for a correlation. This relation suggests a connection between the ionizing continuum and the line emission from the broad emission line region (BELR) of radio-quiet quasars, but in the opposite sense to that predicted by current photoionization models; (5) the correlations of X-ray slope with radio core dominance and FeII equivalent width within the radio-loud and radio-quiet sub-classes respectively imply that the observed wide range of X-ray spectral slopes is real rather than due to the large measuring uncertainties for individual objects.en-USJournal Article2017-02-0819922017-06-0810.1086/172721