Reply to Two Comments on "Dark matter searches going bananas the contribution of Potassium (and Chlorine) to the 3.5 keV line"

Abstract

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.

arXiv comment8 pages, 4 figures

Cited by in corpus (17)

• A facility to Search for Hidden Particles at the CERN SPS: the SHiP physics case
• A White Paper on keV Sterile Neutrino Dark Matter
• Dark Matter Complementarity and the Z${}^{\prime }$ Portal
• Sterile neutrino dark matter: A tale of weak interactions in the strong coupling epoch
• Where do the 3.5 keV photons come from? A morphological study of the Galactic Center and of Perseus
• Deep XMM Observations of Draco rule out at the 99% Confidence Level a Dark Matter Decay Origin for the 3.5 keV Line
• Properties of Resonantly Produced Sterile Neutrino Dark Matter Subhalos
• Dodelson-Widrow Production of Sterile Neutrino Dark Matter with Non-Trivial Initial Abundance
• Les Houches Lectures on Indirect Detection of Dark Matter
• A 3.55 keV line from $\text{DM}\to a\to \gamma$: predictions for cool-core and non-cool-core clusters
• The role of the eROSITA all-sky survey in searches for sterile neutrino dark matter
• A Couplet from Flavored Dark Matter
• Polarization of photons emitted by decaying dark matter
• The Supersymmetric R-Parity Violating Dine-Fischler-Srednicki-Zhitnitsky Axion Model
• The case for mixed dark matter from sterile neutrinos
• Supersymmetric Higgs-portal and X-ray lines
• New emission line at ~3.5 keV - observational status, connection with radiatively decaying dark matter and directions for future studies