We examine the Mg ii absorbing circumgalactic medium ( CGM ) for the 182 intermediate redshift ( 0.072 \leq z \leq 1.120 ) galaxies in the ‘ ‘ Mg ii Absorber-Galaxy Catalog ’ ’ ( MAG ii CAT , Nielsen et al . ) .
We parameterize the anti-correlation between equivalent width , W _ { r } ( 2796 ) , and impact parameter , D , with a log-linear fit , and show that a power law poorly describes the data .
We find that higher luminosity galaxies have larger W _ { r } ( 2796 ) at larger D ( 4.3 ~ { } \sigma ) .
The covering fractions , f _ { c } , decrease with increasing D and W _ { r } ( 2796 ) detection threshold .
Higher luminosity galaxies have larger f _ { c } ; no absorption is detected in lower luminosity galaxies beyond 100 kpc .
Bluer and redder galaxies have similar f _ { c } for D < 100 kpc , but for D > 100 kpc , bluer galaxies have larger f _ { c } , as do higher redshift galaxies .
The ‘ ‘ absorption radius , ’ ’ R ( L ) = R _ { \ast } ( L / L ^ { \ast } ) ^ { \beta } , which we examine for four different W _ { r } ( 2796 ) detection thresholds , is more luminosity sensitive to the B -band than the K -band , more sensitive for redder galaxies than for bluer galaxies , and does not evolve with redshift for the K -band , but becomes more luminosity sensitive towards lower redshift for the B -band .
These trends clearly indicate a more extended Mg ii absorbing CGM around higher luminosity , bluer , and higher redshift galaxies .
Several of our findings are in conflict with other works .
We address these conflicts and discuss the implications of our results for the low-ionization , intermediate redshift CGM .