Reply to Two Comments on "Dark matter searches going bananas the
  contribution of Potassium (and Chlorine) to the 3.5 keV line"
  We respond to two comments on our recent paper, Jeltema & Profumo (2014). The
first comment by Boyarsky et al. confirms the absence of a line from M31 in the
3-4 keV energy range, but criticizes the energy range for spectral fitting on
the basis that (i) the background model adopted between 3-4 keV is invalid
outside that range and that (ii) extending the energy range multiple features
appear, including a 3.5 keV line. Point (i) is manifestly irrelevant (the 3-4
keV background model was not meant to extend outside that range), while closer
inspection of point (ii) shows that the detected features are inconsistent and
likely unphysical. We demonstrate that the existence of an excess near 3.5 keV
in the M31 data requires fitting a broad enough energy range such that the
background modeling near 3.5 keV is poor to a level that multiple spurious
residual features become significant. Bulbul et al. criticize our use of
WebGuide instead of the full AtomDB package. While a technically correct
remark, this is only a red herring: our predictions are based on line ratios,
and not on absolute emissivities; line ratios, for atomic transitions with
similar peak temperatures, are largely temperature-independent, thus the line
ratios we employed to draw our conclusions are substantially correct. Bulbul et
al. also present a new analysis of their data at lower energy, which excludes a
significant Cl contamination to the 3.5 keV line. Cl emission was however
predicted to be subdominant in our original study. Both of the Bulbul et al.'s
criticisms are thus inconsequential to the conclusions of our original study.
Finally, we demonstrate that the multi-temperature models employed in Bulbul et
al. are, in fact, inconsistent, based on the Ca XX to Ca XIX line ratio: we
show that the overestimated cluster plasma temperatures they employ lead to
gross underestimates of the K XVIII line emissivity.
