January 2026 WG3 meeting

Wednesday Feb 25, 2026, 5:00 PM → 6:00 PM Europe/Rome

Maurizio Giannotti

Francesca Lecce will present the talk: Detecting light axions from supernovae in  nearby galaxies

Abstract: Axion-like particles (ALPs) coupled to nucleons can be efficiently produced in core-collapse supernovae (SNe). If they also couple to photons, they can convert into gamma rays in cosmic magnetic fields, generating short gamma-ray bursts. While ALPs from a Galactic SN would produce an intense and easily detectable gamma-ray signal, such events are extremely rare. In contrast, a few SNe per year are expected in nearby galaxies within distances of order 10 Mpc, where strong magnetic fields can allow more efficient ALP–photon conversions than in the Milky Way, making these systems promising extragalactic targets.This motivates full-sky gamma-ray monitoring, ideally combined with decihertz gravitational-wave detectors to enable time-triggered searches from nearby galaxies. We show that, under realistic conditions, a decade of observations could reach sensitivities to the ALP–photon coupling g_agamma greater than approximately 1e-16 GeV⁻¹ for ALP masses below about 1e-9 eV, assuming an ALP–nucleon coupling close to the SN 1987A cooling bound. This sensitivity would allow one to probe a large, currently unexplored region of parameter space below the longstanding SN 1987A bound.

Nearby galaxies Lecce WG3.pdf