Abstract
I have recently proposed that both H i regions of the Galaxy and Lyman-α clouds are mainly ionized by decaying dark matter. Here I point out that to avoid an excessive metagalactic ionizing flux F, the energy of the decay photons must be severely constrained. It then follows that the mass and lifetime τ of the decaying particles, the flux F, the density ρ and age of the Universe, Ω (=ρ/), and the Hubble constant H also have to be severely constrained. The validity of our theory requires that =14.4±0.5 eV, =28.9±1.1 eV, τ=(2+1)× sec, F=(3.8±2.2)× , ρ=(6.14±0.26× g , ∼1.2×yr, Ω∼1, and H=55±1 km .
- Received 15 March 1990
DOI:https://doi.org/10.1103/PhysRevLett.65.2839
©1990 American Physical Society