Forecasting the Observable Rates of Gravitationally Lensed Supernovae for the PASSAGES Dusty Starbursts

Abstract More than 60 years have passed since the first formal suggestion to use strongly lensed supernovae (SNe) to measure the expansion rate of the Universe through time-delay cosmography. Yet, fewer than 10 such objects have ever been discovered. We consider the merits of a targeted strategy focused on lensed hyperluminous infrared galaxies, which are among the most rapidly star-forming galaxies known in the Universe. With star formation rates (SFRs) ∼200–6000 M ⊙ yr −1 , the ∼30 objects in the Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts are excellent candidates for a case study, in particular, and have already led to the discovery of the multiply imaged SN H0pe. Considering their lens model-corrected SFRs, we estimate their intrinsic SN rates to be an extraordinary 1.8–65 yr −1 (core-collapse) and 0.2–6.4 yr −1 (Type Ia). Moreover, these massive starbursts typically have star-forming companions which are unaccounted for in this tally. We demonstrate a strong correlation between Einstein radius and typical time delays, with cluster lenses often exceeding several months (and therefore most favorable for high-precision H 0 inferences). A multivisit monitoring campaign with a sensitive infrared telescope (namely, JWST) is necessary to mitigate dust attenuation. Nevertheless, a porous interstellar medium and clumpy star formation in these extreme galaxies might produce favorable conditions for detecting SNe as transient point sources. Targeted campaigns of known lensed galaxies to discover new lensed SNe can greatly complement wide-area cadenced surveys. Increasing the sample size helps to realize the potential of SN time-delay cosmography to elucidate the Hubble tension through a single-step measurement, independent of other H 0 techniques.