Probing the He II re-Ionization ERa via Absorbing C IV Historical Yield
  (HIERACHY) I: A Strong Outflow from a z~4.7 Quasar
  Outflows from super-massive black holes (SMBHs) play an important role in the
co-evolution of themselves, their host galaxies, and the larger scale
environments. Such outflows are often characterized by emission and absorption
lines in various bands and in a wide velocity range blueshifted from the
systematic redshift of the host quasar. In this paper, we report a strong broad
line region (BLR) outflow from the z~4.7 quasar BR 1202-0725 based on the
high-resolution optical spectrum taken with the Magellan Inamori Kyocera
Echelle (MIKE) spectrograph installed on the 6.5m Magellan/Clay telescope,
obtained from the `Probing the He II re-Ionization ERa via Absorbing C IV
Historical Yield' (HIERACHY) project. This rest-frame ultraviolet (UV) spectrum
is characterized by a few significantly blueshifted broad emission lines from
high ions; the most significant one is the C IV line at a velocity of -6500
km/s relative to the H{\alpha} emission line, which is among the highest
velocity BLR outflows in observed quasars at z > 4. The measured properties of
UV emission lines from different ions, except for O I and Ly{\alpha}, also
follow a clear trend that higher ions tend to be broader and outflow at higher
average velocities. There are multiple C IV and Si IV absorbing components
identified on the blue wings of the corresponding emission lines, which may be
produced by either the outflow or the intervening absorbers.
