Today in MNRAS, I led a paper describing the first 24 campaigns in our ZTF neutrino follow-up program.
We had already published the Tidal Disruption Event (TDE) AT2019dsg and AT2019fdr as probable sources of high-energy neutrinos.
This paper instead focuses on what we did not find. We detail the various candidates we detected but were able to exclude as candidates, and give the overall statistics and efficiencies of our program.
More interestingly, we worked out what neutrino source populations based on our non-detections. If most neutrinos come from a population of bright optical transients, we would have discovered them already. Given that we did not, we can constrain the luminosity function of the as-yet-unknown neutrino sources.
Finally, we considered how these constraints might change over time. We estimated how much better our limits would be if we had followed up the same set of neutrinos with the imminent Rubin Observatory. The results are a little surprising! For very bright sources, the limit would not be much better. However, for more typical sources (e.g supernova at M=-19), Rubin would be a game-changer.
If you’re interested in the details, or watch a quick 5-min summary of the work.