1997/04/10 by D. W. Sciama, Sciama, D. W.
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #FOS: Physical sciences #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9704081
7 pages, LaTeX, uses macro svcon.sty
arxiv created 1997/04/10 · openalex publication_date 1997/04/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The recently constructed Dehnen-Binney set of mass models for the Galaxy is used to show that the decaying neutrino theory for the ionisation of the interstellar medium (Sciama 1990a, 1993) requires the neutrino halo of the Galaxy to be as flattened as is observationally permitted (axial ratio q=0.2 or shape E8). The argument involves an evaluation of the contribution of red-shifted decay photons from the cosmological distribution of neutrinos to the extragalactic diffuse background at 1500 Angstroms. This contribution must be as large as is observationally permitted. These two requirements depend on the decay lifetime in potentially conflicting ways. For consistency to be achieved the lifetime must lie within 30 per cent of 1023 seconds.