The population of planetary nebulae near the Galactic centre: chemical
  abundances
  Planetary nebulae (PNe) constitute an important tool to study the chemical
evolution of the Milky Way and other galaxies, probing the nucleosynthesis
processes, abundance gradients and the chemical enrichment of the interstellar
medium. In particular, Galactic bulge PNe (GBPNe) have been extensively used in
the literature to study the chemical properties of this Galactic structure.
However, the presently available GBPNe chemical composition studies are
strongly biased, since they were focused on brighter objects, predominantly
located in Galactic regions of low interstellar reddening. In this work, we
report physical parameters and abundances derived for a sample of 17 high
extinction PNe located in the inner 2\degr of the Galactic bulge, based on low
dispersion spectroscopy secured at the SOAR telescope using the Goodman
spectrograph. The new data allow us to extend our database including faint
objects, providing chemical compositions for PNe located in this region of the
bulge and an estimation for the masses of their progenitors to explore the
chemical enrichment history of the central region of the Galactic bulge. The
results show that there is an enhancement in the N/O abundance ratio in the
Galactic centre PNe compared with PNe located in the outer regions of the
Galactic bulge. This may indicate recent episodes of star formation occurring
near the Galactic centre.
