Observation of the new emission line at ~3.5 keV in X-ray spectra of galaxies and galaxy clusters

Abstract

The detection of an unidentified emission line in X-ray spectra of cosmic objects would be a 'smoking gun' signature for particle physics beyond the Standard Model. More than a decade of its extensive searches results in several narrow faint emission lines reported at 3.5, 8.7, 9.4 and 10.1 keV. The most promising of them is the emission line at ~3.5 keV reported in spectra of several nearby galaxies and galaxy clusters. Here I summarize its up-to-date status, overview its possible interpretations, including an intriguing connection with radiatively decaying dark matter, and outline future directions for its studies.

17 pages, 7 figures. Accepted by Advances in Astronomy and Space Physics

References in corpus (49)

• The RAVE Survey: Constraining the Local Galactic Escape Speed
• The Quiescent Intracluster Medium in the Core of the Perseus Cluster
• The Observed properties of Dark Matter on small spatial scales
• Dark matter and cosmic structure
• Can sterile neutrinos be the dark matter?
• A lower bound on the mass of Dark Matter particles
• Can sterile neutrinos be ruled out as warm dark matter candidates?
• Kinematic properties of early-type galaxy haloes using planetary nebulae
• Sterile neutrino dark matter as a consequence of nuMSM-induced lepton asymmetry
• How cold is cold dark matter? Small scales constraints from the flux power spectrum of the high-redshift Lyman-alpha forest
• Dwarf galaxy annihilation and decay emission profiles for dark matter experiments
• Where to find a dark matter sterile neutrino?
• Realistic sterile neutrino dark matter with keV mass does not contradict cosmological bounds
• The mass distribution in early-type disk galaxies: declining rotation curves and correlations with optical properties
• Discovery of a 3.5 keV line in the Galactic Center and a Critical Look at the Origin of the Line Across Astronomical Targets
• Resonantly-Produced 7 keV Sterile Neutrino Dark Matter Models and the Properties of Milky Way Satellites
• Direct X-ray Constraints on Sterile Neutrino Warm Dark Matter
• Constraining supernova models using the hot gas in clusters of galaxies
• Constraining DM properties with SPI
• Constraints on the parameters of radiatively decaying dark matter from the dark matter halo of the Milky Way and Ursa Minor
• Constraints on decaying Dark Matter from XMM-Newton observations of M31
• On the hadronic contribution to sterile neutrino production
• Restrictions on parameters of sterile neutrino dark matter from observations of galaxy clusters
• The inner structure of haloes in Cold+Warm dark matter models
• Limits on the Radiative Decay of Sterile Neutrino Dark Matter from the Unresolved Cosmic and Soft X-ray Backgrounds
• A 3.55 keV Photon Line and its Morphology from a 3.55 keV ALP Line
• SIMPle Dark Matter: Self-Interactions and keV Lines
• Strong Upper Limits on Sterile Neutrino Warm Dark Matter
• Self-Scattering for Dark Matter with an Excited State
• Sterile neutrinos in the Milky Way: Observational constraints
• The phase space density of fermionic dark matter haloes
• Searching for decaying dark matter in deep XMM-Newton observation of the Draco dwarf spheroidal
• A novel scenario for the possible X-ray line feature at ~3.5 keV: Charge exchange with bare sulfur ions
• Constraints on the identity of the dark matter from strong gravitational lenses
• Searching for dark matter in X-rays: how not to check the dark matter origin of a spectral feature
• 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
• An X-ray Spectroscopic Search for Dark Matter in the Perseus Cluster with Suzaku
• Generating X-ray lines from annihilating dark matter
• X-ray Lines from Dark Matter: The Good, The Bad, and The Unlikely
• Searching for Dark Matter with X-ray Observations of Local Dwarf Galaxies
• Probing the nature of dark matter with Cosmic X-rays: Constraints from "Dark blobs" and grating spectra of galaxy clusters
• 3.55 keV X-ray Line Signal from Excited Dark Matter in Radiative Neutrino Model
• Wavelet Approach to Search for Sterile Neutrinos in Tritium $\beta$-Decay Spectra
• A 3.55 keV line from $\text{DM}\to a\to \gamma$: predictions for cool-core and non-cool-core clusters
• Nonabelian dark matter models for 3.5 keV X-rays
• A 3.55 keV Line from Exciting Dark Matter without a Hidden Sector
• Observational consistency and future predictions for a 3.5 keV ALP to photon line
• Influence of ~7 keV sterile neutrino dark matter on the process of reionization

Cited by in corpus (17)

• A White Paper on keV Sterile Neutrino Dark Matter
• Hitomi constraints on the 3.5 keV line in the Perseus galaxy cluster
• Constraints on Axion-Like Particles from X-ray Observations of NGC1275
• Closing in on Resonantly Produced Sterile Neutrino Dark Matter
• Light Axinos from Freeze-in: production processes, phase space distributions, and Ly-$\alpha$ forest constraints
• Warm FIRE: Simulating Galaxy Formation with Resonant Sterile Neutrino Dark Matter
• Constraining FIMP from the structure formation of the Universe: analytic mapping from $m_{\mathrm{WDM}}$
• Return of the X-rays: A New Hope for Fermionic Dark Matter at the keV Scale
• Galaxy Formation in Sterile Neutrino Dark Matter Models
• The Doppler effect on indirect detection of dark matter using dark matter only simulations
• Supercritically charged objects and electron-positron pair creation
• Anomalous spectral lines and relic quantum nonequilibrium
• Colder Freeze-in Axinos Decaying into Photons
• Consistency of Hitomi, XMM-Newton and Chandra 3.5 keV data from Perseus
• The 3.5 keV Line from Stringy Axions
• Reviving keV sterile Neutrino Dark Matter
• The Epoch of Reionization in Warm Dark Matter Scenarios