1993/08/31 by Abraham Loeb · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.1103/physrevd.48.r3419
published as Phys.Rev.D48:3419-3421,1993 · 6 pages, TEX, to appear in Physical Review D
arxiv created 1993/08/31 · openalex publication_date 1993/10/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The observed spatial distribution of \ensuremathγ-ray bursts indicates that they probably originate at cosmological distances. At this distance scale their variability time scale and flux above MeV imply an initial optical depth to pair production \ensuremath\gtrsim1010. This appears to be in conflict with their highly nonthermal spectra. We show that this difficulty can be removed if axion bursts from supernovae are converted to \ensuremathγ rays over cosmological distances. Nonthermal bursts with the relevant flux, duration, variability, and spectra are obtained just for the range of axion masses of 10^\ensuremath-5-10^\ensuremath-4 eV that accounts for the cold dark matter in the Universe. The observed rate of \ensuremathγ-ray bursts implies that axions should be converted efficiently to photons in only one out of \ensuremath∼104 supernovae.