Deep XMM Observations of Draco rule out at the 99% Confidence Level a
  Dark Matter Decay Origin for the 3.5 keV Line
  We searched for an X-ray line at energies around 3.5 keV in deep, ~1.6 Msec
XMM-Newton observations of the dwarf spheroidal galaxy Draco. No line was found
in either the MOS or the PN detectors. The data in this energy range are
completely consistent with a single, unfolded power law modeling the particle
background, which dominates at these energies, plus instrumental lines; the
addition of a ~3.5 keV line feature gives no improvement to the fit. The
corresponding upper limit on the line flux rules out a dark matter decay origin
for the 3.5 keV line found in observations of clusters of galaxies and in the
Galactic Center at greater than 99% C.L..
