The spectrum of the quasar PHL~1226 is known to have a strong Mg ii and sub-damped Lyman \alpha ( sub-DLA ) absorption line system with N ( { H \textsc { i } } ) = ( 5 \pm 2 ) \times 10 ^ { 19 } cm ^ { -2 } at z = 0.1602 .
Using integral field spectra from the Potsdam Multi Aperture Spectrophotometer ( PMAS ) we investigate a galaxy at an impact parameter of 6 \aas@@fstack { \prime \prime } 4 which is most probably responsible for the absorption lines .
A fainter galaxy at a similar redshift and a slightly larger distance from the QSO is known to exist , but we assume that the absorption is caused by the more nearby galaxy .
From optical Balmer lines we estimate an intrinsic reddening consistent with 0 , and a moderate star formation rate of 0.5 M _ { \normalsize \odot } \ > yr ^ { -1 } is inferred from the H \alpha luminosity .
Using nebular emission line ratios we find a solar oxygen abundance 12 + \log \textrm { ( O / H ) } = 8.7 \pm 0.1 and a solar nitrogen to oxygen abundance ratio \log \textrm { ( N / O ) } = -1.0 \pm 0.2 .
This abundance is larger than those of all known sub-DLA systems derived from analyses of metal absorption lines in quasar spectra .
On the other hand , the properties are compatible with the most metal rich galaxies responsible for strong Mg ii absorption systems .
These two categories can be reconciled if we assume an abundance gradient similar to local galaxies .
Under that assumption we predict abundances 12 + \log \textrm { ( O / H ) } = 7.1 and \log \textrm { ( N / O ) } = -1.9 for the sub-DLA cloud , which is similar to high redshift DLA and sub-DLA systems .
We find evidence for a rotational velocity of \sim 200 km s ^ { -1 } over a length of \sim 7 kpc .
From the geometry and kinematics of the galaxy we estimate that the absorbing cloud does not belong to a rotating disk , but could originate in a rotating halo .