OPTICAL EMISSION SPECTROSCOPY; QUASARS; VISIBLE SPECTRUM; ABSORPTION SPECTRA; EMISSION SPECTRA; LINE SPECTRA; RED SHIFT; ASTRONOMICAL SPECTROSCOPY
Abstract :
[en] Optical spectroscopy of the three quasars Q0118-031A, B, C is presented. These objects which have emission redshifts of 12.445, 2.112 and 1.165 respectively, form a triplet on the plane of the sky with separations of 4.8, 4.9 and 0.4 arcmins. Low dispersion spectra were obtained for all three objects, and intermediate dispersion spectra instrumental in the search for absorption lines were obtained for objects B and C. QSO B was found to have a rich absorption line spectrum, with definite systems at z(abs) 1.4648 and 2.0192. No absorption lines were found in the given spectrum for QSO C. Estimated column densities and velocity dispersions are given for the absorption systems in QSO B, and it is noted that the one at z(abs) = 1.4648 differs by only 2400 + or - 250 km/s from the emission redshift of QSO A. Since the spatial separation was predicted to be 1.2 Mpc, this absorption system may be due to material related to a galaxy in a cluster which also contains QSO A. It is suggested that this associated absorption is connected to the fact that quasars are located in regions of higher than average matter density.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Robertson, J. G.; Anglo-Australian Observatory, Epping, Australia
Shaver, P. A.; European Southern Observatory, Garching, West Germany
Surdej, Jean ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Swings, Jean-Pierre ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO)