Aims: We use 2D single and multi-thread prominence fine-structure models to obtain the synthetic DEM curves. These are then compared with the DEM curves derived from observations.
Methods: We use the temperature and electron density structure resulting from the 2D models and numerically compute the average synthetic DEM curves for different orientations of the threads with respect to the line of sight.
Results: We show that the synthetic DEM curves obtained by 2D modelling are similar to the DEM curves derived from observations of quiescent prominences.
Conclusions: The DEM curves derived from observations, which are most reliable above temperatures of 20 000 K, can be extended towards cool prominence-core temperatures by supplementing them with synthetic DEM values obtained by modelling hydrogen Lyman spectra originating mainly at temperatures below 20 000 K. On the other hand, the observed DEM can constrain the temperature structure of the prominence fine structures above the formation temperatures of the Lyman spectrum.