Heavy axion-like particles and MeV decay photons from nearby type Ia supernovae

TL;DR

This paper investigates how axion-like particles emitted from nearby Type Ia supernovae could decay into detectable MeV photons, providing a new way to constrain ALP properties with future gamma-ray observations.

Contribution

It models ALP emission from Type Ia supernovae and predicts decay photon signals, offering a novel method to probe ALP parameters using supernova observations.

Findings

ALP luminosity from SNe Ia can reach ~10^43 erg/s for certain parameters.

Decay photons from ALPs could be detected within 1-10 years after a nearby SN Ia.

Constraints on ALP-photon coupling could be as strong as existing limits from SN 1987A.

Abstract

Axion-like particles (ALPs) are hypothetical bosons which may couple with photons. Since many ALPs can be emitted from hot and dense astrophysical plasma, nearby supernovae (SNe) are a possible probe into their properties including the ALP mass m_a and the coupling constant g_{ag} between ALPs and photons. I calculated ALP emission from a type Ia SN (SN Ia) model with the near-Chandrasekhar mass. It is found that the ALP luminosity from SNe Ia reaches ~10^43(g_{ag}/10^-10 GeV^-1)^2 erg s^-1 if m_a < 1 MeV. Heavy ALPs emitted from SNe are unstable and decay into photons. I predict the time delay and the flux of decay photons that reach Earth from a nearby SN Ia. It is found that the decay photons may provide a constraint on g_{ag} which is as stringent as an SN 1987A limit if an SN Ia is located 1 kpc away or closer and next-generation MeV gamma-ray satellites observe it ~1-10 years after the explosion.