Spectroscopy along Multiple, Lensed Sightlines through Outflowing Winds
  in the Quasar SDSS J1029+2623
  We study the origin of absorption features on the blue side of the C IV broad
emission line of the large-separation lensed quasar SDSS J1029+2623 at z_em ~
2.197. The quasar images, produced by a foreground cluster of galaxies, have a
maximum separation angle of ~ 22".5. The large angular separation suggests that
the sight-lines to the quasar central source can go through different regions
of outflowing winds from the accretion disk of the quasar, providing a unique
opportunity to study the structure of outflows from the accretion disk, a key
ingredient for the evolution of quasars as well as for galaxy formation and
evolution. Based on medium- and high-resolution spectroscopy of the two
brightest images conducted at the Subaru telescope, we find that each image has
different intrinsic levels of absorptions, which can be attributed either to
variability of absorption features over the time delay between the lensed
images, ~ 774 days, or to the fine structure of quasar outflows probed by the
multiple sight-lines toward the quasar. While both these scenarios are
consistent with the current data, we argue that they can be distinguished with
additional spectroscopic monitoring observations.
