HE 0141 – 3932 : a bright QSO with an unusual emission line spectrum and associated absorption ⋆

HE 0141–3932 (zem = 1.80) is a bright blue radio-quite quasar with an unusually weak Lyα emission line. Large redshift differences (∆z = 0.05) are observed between high ionization and low ionization emission lines. Absorption systems identified at z abs = 1.78, 1.71, and 1.68 show mild oversolar metallicities (Z ≈ 1 − 2Z⊙) and can be attributed to the associated gas clouds ejected from the circumnuclear region. The joint analysis of the emission and absorption lines leads to the conclusion that this quasar is seen almost pole-on. Its apparent luminosity may be Doppler boosted by ∼ 10 times. The absorbing gas shows a high abundance of Fe, Mg and Al ([Fe, Mg, Al/C] ≃ 0.15 ± 0.10) along with underabundance of N ([N/C] ≤ −0.5). This abundance pattern is at variance with current chemical evolution models of QSOs predicting [N/C] > ∼ 0 and [Fe/C] < 0 at Z ∼ Z⊙.