Galactic nebular lines in the fiber spectra of background QSOs: Reaching
  a hundred QSO-galaxy pairs with spectroscopic and photometric measurements
  We present photometric and spectroscopic measurements of 53 QSO-galaxy pairs
from the Sloan Digital Sky Survey, where nebular emission lines from a 0<z<0.84
foreground galaxy are detected in the fiber spectra of a background QSO,
bringing the overall sample to 103 QSO-galaxy pairs detected in the SDSS. We
here study the nature of these systems. Detected foreground galaxies appear at
impact parameters between 0.37 kpc and 12.68 kpc. The presence of oxygen and
Balmer emission lines allows us to determine the emission line metallicities
for our sample, which are on average super-solar in value. Star formation rates
for our sample are in the range 0.01-12 M_sol yr^-1. We utilize photometric
redshift fitting techniques to estimate the M_stellar values of our galaxies
(log M_stellar = 7.34 - 11.54), and extrapolate this relationship to those
galaxies with no imaging detections. Where available, we measure the absorption
features present in the QSO spectrum due to the foreground galaxy and the
relationships between their rest equivalent widths. We report an
anti-correlation between impact parameter and E(B-V)_(g-i), as well as a
correlation between galaxy color (u-r) and E(B-V)_(g-i). We find that our
sample is one of late-type, star forming galaxies comparable to field galaxies
in a similar redshift range, providing important clues to better understand
absorption systems. These galaxies represent a sample of typical galaxies in
the local Universe for which abundances, extinction, morphology, and absorption
properties may be measured using background QSOs with great potential for
follow-up observations.
