An Iron K Component to the Ultrafast Outflow in NGC 1313 X-1
  We present the detection of an absorpton feature at $E=8.77^{+0.05}_{-0.06}$
keV in the combined X-ray spectrum of the ultraluminous X-ray source NGC 1313
X-1 observed with XMM-Newton and NuSTAR, significant at the 3$\sigma$ level. If
associated with blueshifted ionized iron, the implied outflow velocity is
~0.2$c$ for Fe XXVI, or ~0.25$c$ for Fe XXV. These velocities are similar to
the ultrafast outflow seen in absorption recently discovered in this source at
lower energies by XMM-Newton, and we therefore conclude that this is an iron
component to the same outflow. Photoionization modeling marginally prefers the
Fe XXV solution, but in either case the outflow properties appear to be
extreme, potentially supporting a super-Eddington hypothesis for NGC 1313 X-1.
