Modeling the distribution of Mg II absorbers around galaxies using
  Background Galaxies & Quasars
  We present joint constraints on the distribution of MgII absorption around
galaxies, by combining the MgII absorption seen in stacked background galaxy
spectra and the distribution of host galaxies of strong MgII systems from the
spectra of background quasars. We present a suite of models that predict, the
dependence of MgII absorption on a galaxy's apparent inclination, impact
parameter(b) and azimuthal angle. The variations in the absorption strength
with azimuthal angles provide much stronger constraints on the intrinsic
geometry of the MgII absorption than the dependence on the galaxy's
inclination. Strong MgII absorbers (W_r(2796)>0.3) are asymmetrically
distributed in azimuth around their host galaxies:72% of the absorbers studied
and 100% of the close-in absorbers within b<35 kpc, are located within 50deg of
the host galaxy's projected minor axis. Composite models consisting either of a
simple bipolar component plus a spherical or disk component, or a single highly
softened bipolar distribution, can well represent the azimuthal dependencies
observed in both the datasets. Simultaneously fitting both datasets to the
composite model, bipolar cone is confined to 50deg of the minor axis and
contains 2/3 of the total MgII absorption. The single softened cone model has
an exponential fall off with azimuth with an exponential scale-length in
opening angle of 45deg. We conclude that the distribution of MgII gas at low
impact parameters is not the same as that found at high impact parameters. MgII
absorption within 40 kpc primarily arises from cool MgII gas entrained in
winds. Beyond 40 kpc, there is evidence for a more symmetric distribution,
significantly different from that closer into the galaxies. Here a significant
component appears aligned more with the disk and is possibly inflowing, perhaps
as part of a galactic fountain or the inflow of material from further out in
the system.
