UPDATED PARAMETERS FOR THE DECAYING NEUTRINO THEORY AND EURD OBSERVATIONS OF THE DIFFUSE UV BACKGROUND

Various recent observational developments are here used to make a more critical analysis of the parameter space of the decaying neutrino the ory for the ionisation of the interstellar medium. These developments involve phenomena inside our Galaxy, outside the Galaxy but at essenti ally zero red shift, and at large red shifts. This new analysis leads to a viable theory with a decay lifetime of 2 +/- 1 x 10(23) sec, a de cay photon energy of 13.7 +/- 0.1 eV, and a mass for the decaying neut rino of 27.4 +/- 0.2 eV. These parameters, when combined with some kno wn astronomical quantities, lead to predictions for the intensity, the wavelength and the width of the decay line produced by neutrinos lyin g within one optical depth of the sun (similar to 1/2 pc). One finds a n intensity in the line of 350(-117)(+350) photons cm(-2) sec(-1), a w avelength of 905 +/- 7 Angstrom, and a width similar to 1 Angstrom. Th ese predictions are relevant for the observations about to be made by the EURD ultra-violet detector which is currently in Earth orbit on bo ard the Spanish MINISAT 01 satellite.