A search for emission lines in foreground galaxies in quasar spectra ( z _ { gal } < z _ { QSO } ) of the Sloan Digital Sky Survey ( SDSS ) data release 5 ( DR5 ) reveals 23 examples of quasars shining through low redshift , foreground galaxies at small impact parameters ( < 10 kpc ) .
About 74,000 quasar spectra were examined by searching for narrow H \alpha emission lines at z < 0.38 , at a flux level greater than 5 \times 10 ^ { -17 } ergs cm ^ { -2 } s ^ { -1 } , then confirming that other expected emission lines of the H II regions in the galaxy are detected .
The galaxies were deblended from the quasar images to get colors and morphologies .
For cases that allow the galaxy and the quasar to be deblended , the galaxies are blue ( 0.95 < ( u-r ) < 1.95 ) .
Extinction and reddening through the galaxies is determined from the ( g-i ) color excesses of the quasars .
These reddening values are compared with the flux ratio of H \alpha to H \beta , which reflect the extinction for an undetermined fraction of the sightline through each galaxy .
No trends were found relating E ( B-V ) _ { ( g - i ) } , impact parameter ( b ) , and ( u-r ) for the galaxies or between E ( B-V ) derived from ( g-i ) and that derived from H \alpha /H \beta .
Comparison with previous studies of quasar absorption systems indicate our sample is more reddened , suggesting disk-dominated absorber galaxies .
Measurement or limits on galactic , interstellar Ca II and Na I absorption lines are given from the quasar spectrum .
No trends were found relating Ca II equivalent width ( W ( Ca II ) ) or Na I equivalent width ( W ( Na I ) ) to b , but a correlation of r _ { s } = -0.77 ( \alpha = 0.05 ) was found relating W ( Ca II ) and E ( B-V ) _ { ( g - i ) } .