Emission-line properties of MG 2016+112: A luminous obscured quasar at high redshift*
Astronomical Institute, Tohoku University, Aoba-ku, Sendai 980-77, Japan
2 OMP, 14 Av. E. Belin, 31400 Toulouse, France
Corresponding author: T. Yamada, firstname.lastname@example.org
Accepted: 27 November 2000
We present new high signal-to-noise ratio spectra of the components B and C of the gravitational lensing system MG 2016+112. We show that image C displays strong emission lines of Lyα, NV, CIV, HeII, and CIII] redshifted to , similar to images A and B. We examine the emission-line flux ratios in order to put constraints on the lens models as well as to investigate the intrinsic nature of MG 2016+112. The observed line ratios of B and C are consistent with those expected in the simple photo-ionization models for narrow-line region of active galactic nuclei (AGN) except for the enhanced NV lines. The line ratios difference of components B and C can be interpreted as a difference in ionization parameters. This result is consistent with lens model prediction that C is a fold image of a slightly outer part of the nucleus. MG 2016+112 is known to be very unique among the high-redshift AGN; it is neither an ordinary broad-line quasar nor a powerful radio galaxy as indicated by the width and flux ratio of the emission lines. Together with other observed properties discussed in literature, we argue that MG 2016+112 may be an obscured luminous radio-quiet quasar.
Key words: galaxies: active / galaxies: quasars: emission lines / galaxies: quasars: individual: MG 2016+112
© ESO, 2001