Laboratory measurements compellingly support charge-exchange mechanism for the 'dark matter' $\sim$3.5 keV X-ray line

Abstract

The reported observations of an unidentified X-ray line feature at $\sim$3.5 keV have driven a lively discussion about its possible dark matter origin. Motivated by this, we have measured the \emph{K}-shell X-ray spectra of highly ionized bare sulfur ions following charge exchange with gaseous molecules in an electron beam ion trap, as a source of or a contributor to this X-ray line. We produce ${\mathrm{S}}^{16+}$ and ${\mathrm{S}}^{15+}$ ions and let them capture electrons in collision with those molecules with the electron beam turned off while recording X-ray spectra. We observed a charge-exchanged-induced X-ray feature at the Lyman series limit (3.47 $\pm$ 0.06 keV). The inferred X-ray energy is in full agreement with the reported astrophysical observations and supports the novel scenario proposed by Gu and Kaastra (A \& A \textbf{584}, {L11} (2015)).

arXiv comment7 pages, 6 figures, accepted for publication in ApJ

References in corpus (16)

• Detection of An Unidentified Emission Line in the Stacked X-ray spectrum of Galaxy Clusters
• An unidentified line in X-ray spectra of the Andromeda galaxy and Perseus galaxy cluster
• Updated Atomic Data and Calculations for X-ray Spectroscopy
• Checking the dark matter origin of 3.53 keV line with the Milky Way center
• Non-Detection of X-Ray Emission From Sterile Neutrinos in Stacked Galaxy Spectra
• A novel scenario for the possible X-ray line feature at ~3.5 keV: Charge exchange with bare sulfur ions
• Deep XMM Observations of Draco rule out at the 99% Confidence Level a Dark Matter Decay Origin for the 3.5 keV Line
• Plasma code for astrophysical charge exchange emission at X-ray wavelengths
• Polarization measurement of dielectronic recombination transitions in highly charged krypton ions
• Charge Exchange Spectra of Hydrogenic and He-like Iron
• Charge Exchange Induced X-ray Emission of Fe XXV and Fe XXVI via a Streamlined Model
• Strong higher-order resonant contributions to x-ray line polarization in hot plasmas
• Ne X X-ray Emission due to Charge Exchange in M82
• Investigation of slow collisions for (quasi) symmetric heavy systems: what can be extracted from high resolution X-ray spectra
• Critical Test of Simulations of Charge-Exchange-Induced X-Ray Emission in the Solar System
• Measurement of anomalously strong emission from the 1s-9p transition in the spectrum of H-like phosphorus following charge exchange with molecular hydrogen

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