Molecular ionization rates and ultracompact dark matter minihalos

Abstract

Molecular ionization in the Central Molecular Zone of our galaxy is enhanced over the typical galactic value by an order of magnitude or more. This cannot be easily explained for dense Galactic Center molecular complexes in the absence of embedded sources of low energy cosmic rays. We provide such a source in the form of ultracompact minihalos of self-annihilating dark matter for a variety of annihilation channels that depend on the particle mass and model. Such sources are motivated for plausible inflationary power spectrum parameters, and while possibly subdominant in terms of the total dark matter mass within the Galactic bulge, might also account for, or at least not be in tension with, the Fermi Galactic Centre γ-ray excess.

5 pages

References in corpus (19)

• The merger rate of primordial-black-hole binaries
• Physical properties of molecular clouds for the entire Milky Way disk
• Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution
• Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
• Primordial Black Holes from Inflation and non-Gaussianity
• The Fermi-LAT GeV Excess Traces Stellar Mass in the Galactic Bulge
• Density profiles of ultracompact minihalos: Implications for constraining the primordial power spectrum
• Are ultracompact minihalos really ultracompact?
• Star formation in a high-pressure environment: An SMA view of the Galactic centre dust ridge
• What causes the ionization rates observed in molecular clouds? The role of cosmic ray protons and electrons
• Constraints on small-scale primordial power by annihilation signals from extragalactic dark matter minihalos
• Galactic Binaries Can Explain the Fermi Galactic Center Excess and 511 keV Emission
• Millisecond pulsar origin of the Galactic center excess and extended gamma-ray emission from Andromeda - a closer look
• Constraints on the Cosmic-Ray Ionization Rate in the $z\sim 2.3$ Lensed Galaxies SMM J2135$-$0102 and SDP 17b from Observations of OH${}^{+}$ and H${}_2$O${}^{+}$
• On the Origin of the 511 keV Emission in the Galactic Centre
• HCN $J$=4-3, HNC $J$=1-0, ${\mathrm{H}}^{13}\mathrm{CN}$ $J$=1-0, and $\mathrm{H}{\mathrm{C}}_3\mathrm{N}$ $J$=10-9 Maps of Galactic Center Region I: Spatially-Resolved Measurements of Physical Conditions and Chemical Composition
• Pevatron at the Galactic Center: Multi-Wavelength Signatures from Millisecond Pulsars
• The CARMA 3mm Survey of the Inner $0.7^{\circ }\times 0.4^{\circ }$ of the Central Molecular Zone
• A study of methanol and silicon monoxide production through episodic explosions of grain mantles in the Central Molecular Zone

Cited by in corpus (1)

• Ultracompact minihalos associated with stellar-mass primordial black holes