Expectation for the MeV Gamma-Ray Emission from Pair-Instability Supernovae

Abstract

Pair-instability supernovae (PISNe) are predicted thermonuclear explosions of massive stars with helium core masses exceeding $\sim 65M_{\odot }$ and synthesize substantial amounts of radioactive ${}^{56}\mathrm{Ni}$ ($M({}^{56}\mathrm{Ni})\sim 60M_{\odot }$ in extreme cases). To investigate their observational signatures, we developed a multi-D Monte Carlo radiation transport code, assuming spherical symmetry in the background medium and the photon sources distribution, and performed simulations of gamma-ray and hard X-ray emissions from the decay chain ${}^{56}\mathrm{Ni}\to {}^{56}\mathrm{Co}\to {}^{56}\mathrm{Fe}$. We find that key gamma-ray lines (847 and 1238 keV) from ${}^{56}\mathrm{Co}$ decay in the $130M_{\odot }$ helium core model can be detected up to 300-400 Mpc by next-generation MeV gamma-ray telescopes. In contrast, the signals from the $100M_{\odot }$ model remain below the detection limits. Our results provide the template for gamma-ray follow-up observations of PISNe. Considering theoretical predictions and observational constraints, we estimate PISN event rates within 300 Mpc to be approximately 0.01-0.1 events per year, highlighting their rarity but also emphasizing their feasibility as targets for future gamma-ray observations over the decade.

11 pages, 6 figures, accepted for publication in The Astrophysical Journal

References in corpus (18)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Pre-Supernova Evolution of Massive Single and Binary Stars
• Pulsational Pair-Instability Supernovae
• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• Mind the gap: The location of the lower edge of the pair instability supernovae black hole mass gap
• Super-luminous supernovae at redshifts of 2.05 and 3.90
• Precision Study of Positronium: Testing Bound State QED Theory
• GW190521 may be an intermediate mass ratio inspiral
• SN2014J gamma-rays from the 56Ni decay chain
• Fast evolving pair-instability supernova models: evolution, explosion, light curves
• Possible pair-instability supernovae at solar metallicity from magnetic stellar progenitors
• Formation of black holes in the pair-instability mass gap: evolution of a post-collision star
• Extending the supernova Hubble diagram to z~1.5 with the Euclid space mission
• Expectations for the Hard X-ray Continuum and Gamma-ray Line Fluxes from the Type Ia supernova SN 2014J in M82
• EMPRESS. IV. Extremely Metal-Poor Galaxies (EMPGs) Including Very Low-Mass Primordial Systems with M*=10^4--10^5 M_sun and 2--3% (O/H)_sun: High (Fe/O) Suggestive of Metal Enrichment by Hypernovae/Pair-Instability Supernovae
• Pair-Instability Supernova Simulations: Progenitor Evolution, Explosion, and Light Curves
• Impacts of the ${}^{12}\mathrm{C}{\left(\alpha ,\gamma \right)}^{16}\mathrm{O}$ reaction rate on ${}^{56}\mathrm{Ni}$ nucleosynthesis in pair-instability supernovae