EVIDENCE AGAINST SOME ORIENTATION EFFECTS IN RADIO-QUIET QUASARS

The model of radio-loud quasars which unifies lobe- and core-dominated objects through orientation has been used in the past to interpret observations of optical emission lines. This approach leads to a prediction that objects with broader permitted lines should have forbidden lines with larger equivalent width. Using recent observations of a complete sample of bright, low-redshift, radio-quiet quasars, it is shown that this correlation is not present. A Monte Carlo simulation indicates that the observed lack of correlation is inconsistent with the proposed orientation dependence for these properties. One possible explanation is that radio-loud quasars contain a beamed continuum component which is lacking in radio-quiet quasars. A second possibility is that the correlations seen in radio-loud quasars are not due to orientation but to intrinsic differences. The same test applied to a radio-loud sample shows only a weak correlation, suggesting that the variation in at least one of the emission-line properties is not due to orientation.