SIMBAD references

We have analyzed the population of Galactic bulge planetary nebulae (GBPN) by means of Monte-Carlo methods. Statistical tests were used to compare observed histograms with simulated distributions of radio fluxes, angular diameters, surface brightnesses and nebular ionized masses. We have shown how selection effects operate in observed diagrams and alter our understanding of the GBPN population: for example, the observed central star mass distribution is biased upwards with respect to the intrinsic one. The present observational constraints allow a large number of solutions, and it is essential to measure the nebular expansion velocities for a better understanding of the GBPN population. Still, all the accepted solutions correspond to a very narrow central star mass distribution, centered on a value not larger than 0.6M_☉. Incidentally, we have found that, in the synthetic populations which are compatible with the observations, there is a large proportion of density bounded nebulae. This is an important result for studies of the HR diagram for central stars.