INTEGRAL Limits on Past High-energy Activity from FRB 20200120E in M81

Abstract

The repeating fast radio burst FRB 20200120E is located in a globular cluster belonging to the nearby M81 galaxy. Its small distance (3.6 Mpc) and accurate localization make it an interesting target to search for bursting activity at high energies. From 2003 November to 2021 September, the INTEGRAL satellite has obtained an exposure time of 18 Ms on the M81 sky region. We used these data to search for hard X-ray bursts from FRB 20200120E using the IBIS/ISGRI instrument, without finding any significant candidate, down to an average fluence limit of ∼10⁻⁸ erg cm⁻² (20–200 keV). The corresponding limit on the isotropic luminosity for a burst of duration Δt is erg s⁻¹, the deepest limit obtained for an extragalactic FRB in the hard X-ray range. This rules out the emission of powerful flares at a rate higher than 0.1 yr⁻¹ that could be expected in models invoking young hyperactive magnetars.