We present ISM and CGM metallicities for 25 absorption systems associated with isolated star-forming galaxies ( \left < z \right > = 0.28 ) with 9.4 \leq log ( M _ { * } /M _ { \odot } ) \leq 10.9 and with absorption detected within 200 kpc .
Galaxy ISM metallicities were measured using H \alpha / [ N ii ] emission lines from Keck/ESI spectra .
CGM single-phase low-ionization metallicities were modeled using MCMC and Cloudy analysis of absorption from HST /COS and Keck/HIRES or VLT/UVES quasar spectra .
We find that the star-forming galaxy ISM metallicities follow the observed stellar mass metallicity relation ( 1 \sigma scatter 0.19 dex ) .
CGM metallicity shows no dependence with stellar mass and exhibits a scatter of \sim 2 dex .
All CGM metallicities are lower than the galaxy ISM metallicities and are offset by log ( dZ ) = -1.17 \pm 0.11 .
There is no obvious metallicity gradient as a function of impact parameter or virial radius ( < 2.3 \sigma significance ) .
There is no relationship between the relative CGM–galaxy metallicity and azimuthal angle .
We find the mean metallicity differences along the major and minor axes are - 1.13 \pm 0.18 and - 1.23 \pm 0.11 , respectively .
Regardless of whether we examine our sample by low/high inclination or low/high impact parameter , or low/high N ( H i ) , we do not find any significant relationship with relative CGM–galaxy metallicity and azimuthal angle .
We find that 10/15 low column density systems ( logN ( H i ) < 17.2 ) reside along the galaxy major axis while high column density systems ( logN ( H i ) \geq 17.2 ) reside along the minor axis .
This suggest N ( H i ) could be a useful indicator of accretion/outflows .
We conclude that CGM is not well mixed , given the range of galaxy-CGM metallicities , and that metallicity at low redshift might not be a good tracer of CGM processes .
On the-other-hand , we should replace integrated line-of-sight , single phase , metallicities with multi-phase , cloud-cloud metallicities , which could be more indicative of the physical processes within the CGM .