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Understanding the origin of the positron annihilation line and the physics of supernova explosions

Frontera, F, Virgilli, E, Guidorzi, C, Rosati, P, Diehl, R, Siegert, T, Fryer, C, Amati, L, Auricchio, N, Campana, R, Caroli, E, Fuschino, F, Labanti, C, Orlandini, M, Pian, E, Stephen, JB, Del Sordo, S, Budtz-Jorgensen, C, Kuvvetli, I, Brandt, S , da Silva, RMC, Laurent, P, Bozzo, E, Mazzali, P and Della Valle, M (2021) Understanding the origin of the positron annihilation line and the physics of supernova explosions. Experimental Astronomy, 51 (3). pp. 1175-1202. ISSN 0922-6435

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Abstract

Nuclear astrophysics, and particularly nuclear emission line diagnostics from a variety of cosmic sites, has remained one of the least developed fields in experimental astronomy, despite its central role in addressing a number of outstanding questions in modern astrophysics. Radioactive isotopes are co-produced with stable isotopes in the fusion reactions of nucleosynthesis in supernova explosions and other violent events, such as neutron star mergers. The origin of the 511 keV positron annihilation line observed in the direction of the Galactic Center is a 50-year-long mystery. In fact, we still do not understand whether its diffuse large-scale emission is entirely due to a population of discrete sources, which are unresolved with current poor angular resolution instruments at these energies, or whether dark matter annihilation could contribute to it. From the results obtained in the pioneering decades of this experimentally-challenging window, it has become clear that some of the most pressing issues in high-energy astrophysics and astro-particle physics would greatly benefit from significant progress in the observational capabilities in the keV-to-MeV energy band. Current instrumentation is in fact not sensitive enough to detect radioactive and annihilation lines from a wide variety of phenomena in our and nearby galaxies, let alone study the spatial distribution of their emission. In this White Paper (WP), we discuss how unprecedented studies in this field will become possible with a new low-energy gamma-ray space experiment, called ASTENA (Advanced Surveyor of Transient Events and Nuclear Astrophysics), which combines new imaging, spectroscopic and polarization capabilities. In a separate WP (Guidorzi et al. 39), we discuss how the same mission concept will enable new groundbreaking studies of the physics of Gamma–Ray Bursts and other high-energy transient phenomena over the next decades.

Item Type: Article
Uncontrolled Keywords: Science & Technology; Physical Sciences; Astronomy & Astrophysics; X-/gamma-ray telescopes; Space mission concept; ESA voyage 2050; Origin of positron annihilation line from Galactic bulge region; Dark matter from the Galactic Center region; Nucleosynthesis study in novae; type I and core-collapse supernovae; Physical origin of the Phillips law; Nuclear line distribution across supernova remnants; RAY EMISSION-LINES; HARD-X-RAY; GAMMA-RAYS; RADIATION; TI-44; DETECTOR; DECAY; SCINTILLATOR; POLARIMETRY; DISCOVERY; 0201 Astronomical and Space Sciences; Astronomy & Astrophysics
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: Springer (part of Springer Nature)
SWORD Depositor: A Symplectic
Date Deposited: 02 Nov 2022 10:43
Last Modified: 02 Nov 2022 10:45
DOI or ID number: 10.1007/s10686-021-09727-7
URI: https://researchonline.ljmu.ac.uk/id/eprint/17991
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