• The determination of the abundance of heavy elements (e.g. O, N, S, Ar) in gaseous nebulae provide crucial information to study the history of star formation and chemical enrichment of the Unvierse. Despite recent spectroscopic observations and surveys (CALIFA, SDSS, MaNGA, MUSE, and CHAOS, to cite a few) have provided significant advances in the knowledge of the chemical compositions of gaseous nebulae and their host galaxies, but some key aspects in the study of these objects remain ill-defined.

    In particular, the abundance discrepancy problem in HII regions and planetary nebulae, generally interpreted as caused by the presence of temperature fluctuations, puts under scrutiny the nebular abundance scale of the Milky Way and extragalactic objects. Moreover, the determination chemical abundances and ionisation correction factors, both local and at high-redshift, still suffer strong dependences on the photoionization conditions and on the different methods and models used for the analysis.

    This 5-days workshop aims at bringing together scientists and students to extensively discuss about the crucial questions on chemical abundances in gaseous nebulae, the recent progress in the field and how next generation observing facilities (such as the James Webb Space Telescope and Extremely Large Telescopes will enable major steps forward in this area of research.

    Main topics:

    - Abundance discrepancy in HII regions and Planetary Nebulae

    - Methods to determine the chemical abundance in gaseous nebulae

    - Ionization correction factors of HII regions and Planetary Nebulae

    - Determination of chemical abundances in AGN and high redshift galaxies

    - Implications of chemical abundances in gaseous nebulae in understanding galaxy evolution

    - Ultraviolet, optical and infrared spectroscopy of gaseous nebulae

    - Abundance determinations in AGNs

    - Atomic parameters

    - Implications of next generation telescopes on chemical abundance determinations in gaseous nebulae

    - Recent surveys and projects on chemical abundances in gaseous nebulae and AGNs