GEOMETRIC DIFFERENCES BETWEEN THE GASEOUS AND STELLAR WARPS IN THE MILKY-WAY

Careful modelling of the stellar and gaseous distributions in the Milk y Way disc has been carried out in order to study the stellar warp. We have analysed the observations in the near infrared made by the ''Dif fuse Infrared Background Experiment'' (DIRBE) on board COBE as reporte d by Freudenreich et al. (1994). These authors found a dependence of t he displacement of the maximum emission on galactic longitude, which i s however less than that observed at 21 cm. Our model enables us to re ject the interpretation of this displacement as being due to the fact that the Sun does not exactly lie in the galactic plane. Either the st ellar disc is large but is less warped than the gaseous disc, or it ha s a cutoff at r less than or similar to 15 kpc. preliminary results fr om DENIS (Ruphy et al. 1996) indicate a cutoff at 15 kpc, favouring th e latter interpretation.