One-Photon Annihilation of Nonthermal Positrons in the Interstellar Medium
1996; IOP Publishing; Volume: 457; Linguagem: Inglês
10.1086/176742
ISSN1538-4357
Autores Tópico(s)Electron and X-Ray Spectroscopy Techniques
Resumoview Abstract Citations (7) References (8) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS One-Photon Annihilation of Nonthermal Positrons in the Interstellar Medium Jung, Young-Dae Abstract In the nonrelativistic limit, the direct one-photon annihilation rate of nonthermal positrons with bound atomic electrons is calculated. For various spectral power indices, the total annihilation rate of positrons with an atom is calculated by considering the K- and L-shell contributions. The total number of one-photon annihilation events for the abundant interstellar elements (H, He, C, N, O, Ne, Mg, Si, S, and Fe) with respect to the hydrogen atom are evaluated. The result shows that in the interstellar medium the main contributors to one-photon positron annihilations are Fe, O, and Si atoms for low power index (F = 6), Fe, H, and He atoms for intermediate power index (Γ = 7), and H, He, and 0 atoms for high power indices (Γ = 8-10). The total number of annihilation events is quickly decreasing with increasing power index. The L-shell contribution is increased as the power index increases; for example, the L-shell contribution of atomic oxygen is about 6% and 38% for Γ = 6 and 10, respectively. Publication: The Astrophysical Journal Pub Date: January 1996 DOI: 10.1086/176742 Bibcode: 1996ApJ...457..431J Keywords: ATOMIC PROCESSES; ELEMENTARY PARTICLES; ISM: GENERAL full text sources ADS |
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