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The properties of the emission-line regions in 16 broad absorption line (BAL) quasars are compared to those of non-BAL quasars. It is found that about half the BAL quasars, those having detached BALs, are significantly different from the comparison samples of normal quasars. They have large Al III/semiforbidden C III intensity ratios, strong Fe II emission, and unusually weak C IV emission lines whose profiles do not agree well with those of the lower ionization emission lines. New spectra of the Mg II 2798 A region in 13 of these BAL quasars show a few cases of possible weak Mg II BAL absorption, but no unambiguously strong cases. Thus, it is concluded that strong BAL absorption in Mg II is rare. The quasar H0335 -336 has very narrow emission lines (1000 km/s), and thus may offer a rare opportunity to measure many weak or normally blended emission lines which can give information about physical conditions in the emission-line gas.
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Hartig et al. (1986) studied this question.
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