Dark matter decay and the ionization of H I regions in the Galaxy

Abstract

It is argued that the observed constancy of the free electron density in H I regions near the sun, and its relatively large scale height of about 900 pc, can be naturally explained if dark matter in the Galaxy is producing hydrogen-ionizing photons on a time scale about 1.5 x 10 to the 23rd sec. This model leads to a variety of other consequences in astronomy and cosmology, some of which are already supported by observation. These consequences include a well-defined rotation curve for the Galaxy, a strong flattening of its dark halo, and, if the particles are neutrinolike, well-defined values for the energy of the photons (13.8 + or - 0.2 eV), for the rest mass of the particles (27.7 + or - 0.5 eV), for the mean density of the universe (5.94 + or - 0.24 x 10 the -30th g/cu cm) and, if this density is critical, for the age of the universe (12 Gyr) and the the Hubble constant (54.5 + or - 1 km/sec Mpc).