Spectroscopy of the double quasars Q1343+266A, B: The relationship between galaxies and quasi-stellar object C IV absorption lines

We present spectra of QSOs Q1343+266A, B, covering Lyβ to C IV emission at 2 Å resolution, and find further evidence that this system is not gravitationally lensed. We see, however, a large number of Lyα and some C IV absorption features common to both spectra. The frequency of C IV lines in common indicates that these absorbers have a radius close to the sight line separation, 39 h^-1 kpc (q₀ = 0.5), implying a spatial number density of these absorbers the same as current-day L > 0.3 L_* galaxies. Furthermore, the velocity mismatch for C IV systems indicates absorber masses in the range 10¹¹ M_⊙ < M < 10¹² M_⊙. These results confirm that typical galaxies cause QSO C IV-line absorption.