Revised Gaia Data Release 2 passbands

I/345) a catalogue of photometric measurements for more than 1.3 billion astronomical objects in three passbands. The precision of the measurements in these passbands, denoted G, G_BP_, and G_RP_, reaches down to the milli-magnitude level.

The scientific exploitation of this data set requires precise knowledge on the response curves of the three passbands. This work aims for improving the exploitation of the photometric data by deriving an improved set of response curves for the three passbands, allowing for an accurate computation of synthetic Gaia photometry. This is achieved by formulating the problem of passband determination in a functional analytic formalism, and linking the photometric measurements with four observational, one empirical and one theoretical spectral library.