HST/COS Spectra of Three QSOs That Probe The Circumgalactic Medium of a
  Single Spiral Galaxy: Evidence for Gas Recycling and Outflow
  We have used the Cosmic Origins Spectrograph (COS) to obtain far-UV spectra
of three closely-spaced QSO sight lines that probe the circumgalactic medium
(CGM) of an edge-on spiral galaxy, ESO 157-49, at impact parameters of 74 and
93 kpc near its major axis and 172 kpc along its minor axis. H I Ly\alpha\
absorption is detected at the galaxy redshift in the spectra of all three QSOs,
and metal lines of Si III, Si IV, and C IV are detected along the two
major-axis sight lines. Photoionization models of these clouds suggest
metallicities close to the galaxy metallicity, cloud sizes of ~1 kpc, and gas
masses of ~10^4 solar masses. Given the high covering factor of these clouds,
ESO 157-49 could harbor ~2x10^9 solar masses of warm CGM gas. We detect no
metals in the sight line that probes the galaxy along its minor axis, but gas
at the galaxy metallicity would not have detectable metal absorption with
ionization conditions similar to the major-axis clouds. The kinematics of the
major-axis clouds favor these being portions of a "galactic fountain" of
recycled gas, while two of the three minor-axis clouds are constrained
geometrically to be outflowing gas.
  In addition, one of our QSO sight lines probes a second more distant spiral,
ESO 157-50, along its major axis at an impact parameter of 88 kpc. Strong H I
Ly\alpha\ and C IV absorption only are detected in the QSO spectrum at the
redshift of ESO 157-50.
