Sub-keV dark matter can strongly ionize molecular clouds

Abstract

We show that the ionization of dense molecular clouds can be used to set strong constraints on dark matter models producing UV/X-ray photons in their annihilation or decay. We place robust and competitive constraints on various dark matter models, such as axion-like particles, scalars and sterile neutrinos, for masses between $\sim 30$~eV and $10$~keV, and project forecasts to illustrate the potential of this target. We discuss how these constraints can be significantly improved by considering a more refined sample of molecular clouds near the Galactic Center and above the Galactic plane, a detailed modeling of the cosmic-ray ionization contribution and, potentially, a more refined analysis of the gas density in clouds through dust extinction maps. Thus, ionization of molecular clouds emerges as one of the most powerful tools for probing sub-keV dark matter.

9 pages plus appendices, 8 figures. Comments are welcome! This version matches published version and contains both, main text and Supp. material

References in corpus (69)

• Cold Dark Clouds: The Initial Conditions for Star Formation
• PPPC 4 DM ID: A Poor Particle Physicist Cookbook for Dark Matter Indirect Detection
• Is the Lightest Kaluza-Klein Particle a Viable Dark Matter Candidate?
• The landscape of QCD axion models
• Light Dark Matter Search with Ionization Signals in XENON1T
• Z-prime Gauge Bosons at the Tevatron
• Indirect Dark Matter Signatures in the Cosmic Dark Ages I. Generalizing the Bound on s-wave Dark Matter Annihilation from Planck
• Vector Dark Matter from Inflationary Fluctuations
• Revisiting the bound on axion-photon coupling from Globular Clusters
• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
• Sterile Neutrino Dark Matter
• Cosmic-ray ionization of molecular clouds
• Investigating the Cosmic-Ray Ionization Rate in the Galactic Diffuse Interstellar Medium through Observations of H3+
• Bosonic super-WIMPs as keV-scale dark matter
• Axion dark matter from topological defects
• The Dark Photon
• Constraining Light Dark Matter with Diffuse X-Ray and Gamma-Ray Observations
• Cosmological bounds on pseudo Nambu-Goldstone bosons
• Dark photon limits: a handbook
• Herschel Survey of Galactic OH+, H2O+, and H3O+: Probing the Molecular Hydrogen Fraction and Cosmic-Ray Ionization Rate
• keV sterile neutrino dark matter in gauge extensions of the standard model
• Massive hidden photons as lukewarm dark matter
• The origin of Galactic cosmic rays: challenges to the standard paradigm
• A fresh look at linear cosmological constraints on a decaying dark matter component
• Recent Progress in the Physics of Axions and Axion-Like Particles
• The Search for Feebly-Interacting Particles
• A deep search for decaying dark matter with XMM-Newton blank-sky observations
• Strongest model-independent bound on the lifetime of Dark Matter
• The characteristics of the Galactic center excess measured with 11 years of Fermi-LAT data
• Astrophysical Axion Bounds: The 2024 Edition
• The Implications of a High Cosmic-Ray Ionization Rate in Diffuse Interstellar Clouds
• An even lighter QCD axion
• Light Weakly Coupled Axial Forces: Models, Constraints, and Projections
• Constraints on the coupling with photons of heavy axion-like-particles from Globular Clusters
• Spectral distortion constraints on photon injection from low-mass decaying particles
• The Ionization Fraction of Barnard 68: Implications for Star and Planet Formation
• Strong constraints on decay and annihilation of dark matter from heating of gas-rich dwarf galaxies
• Gas-rich dwarf galaxies as a new probe of dark matter interactions with ordinary matter
• Galactic Center Gas Clouds and Novel Bounds on Ultra-Light Dark Photon, Vector Portal, Strongly Interacting, Composite, and Super-Heavy Dark Matter
• Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey
• Uncertainties in the Galactic dark matter distribution: an update
• Calorimetric Dark Matter Detection With Galactic Center Gas Clouds
• Stellar limits on scalars from electron-nucleus bremsstrahlung
• Bounds on Long-lived Dark Matter Mediators from Neutron Stars
• Simulations of axion-like particles in the post-inflationary scenario
• Low energy cosmic rays
• Gravitational waves from axion-like particle cosmic string-wall networks
• Dark Photon Decay Beyond The Euler-Heisenberg Limit
• What causes the ionization rates observed in molecular clouds? The role of cosmic ray protons and electrons
• Axion Astrophysics
• A new life for sterile neutrino dark matter after the pandemic
• Constraining heavy axion-like particles by energy deposition in Globular Cluster stars
• Effective Shielding of $\lesssim$ 10 GeV Cosmic Rays from Dense Molecular Clumps
• Stochasticity of Cosmic Rays from Supernova Remnants and the Ionization Rates in Molecular Clouds
• Detectable and defect-free dark photon dark matter
• X-Ray Constraints on Dark Photon Tridents
• Experimental targets for dark photon dark matter
• Comment on the paper "Calorimetric Dark Matter Detection with Galactic Center Gas Clouds"
• Stellar limits on light CP-even scalar
• On the Origin of the 6.4 keV Line in the Galactic Center Region
• Leading bounds on micro- to picometer fifth forces from neutron star cooling
• Astrochemical modelling of infrared dark clouds
• Anomalous Ionization in the Central Molecular Zone by sub-GeV Dark Matter
• Cosmic rays cannot explain the high ionisation rates in the Galactic centre
• A Spectroscopic Search for Optical Emission Lines from Dark Matter Decay
• A sensitive search for unknown spectral emission lines in the diffuse X-ray background with XMM-Newton
• Extra-dimensional axion patterns
• Hunting for Dark Photon-Photon Tridents
• Particle dispersion in the classical vector dark matter background

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• Strong Constraints on Dark Photon and Scalar Dark Matter Decay from INTEGRAL and AMS-02 data
• INTEGRAL, eROSITA and Voyager Constraints on Light Bosonic Dark Matter: ALPs, Dark Photons, Scalars, $B-L$ and $L_i-L_j$ Vectors