  While first order phase transitions (FOPTs) have been extensively studied as
promising cosmological sources of gravitational waves, the phenomenon of
particle production from the dynamics of the background field during FOPTs has
received relatively little attention in the literature, where it has only been
studied with semi-analytic estimates in some simplified settings. This paper
provides improved numerical studies of this effect in more realistic
frameworks, revealing important qualitative details that have been missed in
the literature. We also provide easy to use analytic formulae that can be used
to calculate particle production in generic FOPT setups.
