Mg II Absorption Characteristics of a Volume-Limited Sample of Galaxies
  at z ~ 0.1
  We present an initial survey of Mg II absorption characteristics in the halos
of a carefully constructed, volume-limited subsample of galaxies embedded in
the spectroscopic part of the Sloan Digital Sky Survey. We observed quasars
near sightlines to 20 low-redshift (z ~ 0.1), luminous M_r <= -20.5 galaxies in
SDSS DR4 and DR6 with the LRIS-B spectrograph on the Keck I telescope. The
primary systematic criteria for the targeted galaxies are a redshift z >~ 0.1
and the presence of an appropriate bright background quasar within a projected
75 kpc/h of its center, although we preferentially sample galaxies with lower
impact parameters and slightly more star formation within this range. Of the
observed systems, six exhibit strong [EW(2796) >= 0.3 Ang.] Mg II absorption at
the galaxy's redshift, six systems have upper limits which preclude strong Mg
II absorption, while the remaining observations rule out very strong [EW(2796)
>= 1-2 Ang] absorption. The absorbers fall at higher impact parameters than
many non-absorber sightlines, indicating a covering fraction f_c <~ 0.4 for >=
0.3-Angstrom absorbers at z ~ 0.1, even at impact parameters <= 35 kpc/h (f_c ~
0.25). The data are consistent with a possible dependence of covering fraction
and/or absorption halo size on the environment or star-forming properties of
the central galaxy.
