Supernovae fireworks: Increased luminosity of galaxies ~500-800 Myr after the Big Bang

Abstract Unraveling the problem of impossibly early galaxies, we propose a model in which a galaxy’s luminosity consistently depends on two types of stars that differ only in mass and thus have different types of their evolution. At the initial stage, up to 1 Gyr from the Big Bang, the luminosity is mostly determined by stars with masses greater than 8М🖸, which have a short life cycle and inevitably end their evolution with supernovae outbursts. But then, in the later Universe, the galaxy luminosity function (GLF) begins to depend on the much more numerous stars with masses less than 8М🖸, which continue on the main sequence. Thus, we find that the initial increased luminosity (“supernovae fireworks”) occurs at much lower galaxy masses. To evaluate the hypothesis, we propose an observational test, where we measure the luminosity irregularities (> 3σ) of those six too bright early galaxies, to be taken over a period of 8–12 months.