Physics

Luminosity

Supernova

Sociology

Population

Galaxy

Demography

RADIUS

Neutrino

Photon

Composite material

Nuclear physics

Materials science

Range (aeronautics)

Computer science

Astrophysics

Quantum mechanics

Ejecta

Computer security

Radiative transfer

Physical Review Letters

The hot and dense core formed in the collapse of a massive star is a powerful source of hypothetical feebly interacting particles such as sterile neutrinos, dark photons, axionlike particles (ALPs), and others. Radiative decays such as a→2γ deposit this energy in the surrounding material if the mean free path is less than the radius of the progenitor star. For the first time, we use a supernova (SN) population with particularly low explosion energies as the most sensitive calorimeters to constrain this possibility. These SNe are observationally identified as low-luminosity events with low ejecta velocities and low masses of ejected ^{56}Ni. Their low energies limit the energy deposition from particle decays to less than about 0.1 B, where 1 B(bethe)=10^{51} erg. For 1-500 MeV-mass ALPs, this generic argument excludes ALP-photon couplings G_{aγγ} in the 10^{-10}-10^{-8} GeV^{-1} range.

Low-Energy Supernovae Severely Constrain Radiative Particle Decays