Contreras, C. S. (2020). (Sub)mm-Wavelength Observations of Pre-Planetary Nebulae and Young Planetary Nebulae. Galaxies 8, 1 DOI: 10.3390/galaxies8010021
This is a non-comprehensive review of observations of pre-Planetary Nebulae (pPNe) and young Planetary Nebulae (yPNe) at (sub)mm-wavelengths, a valuable window for probing multi-phased gas and dust in these objects. This contribution focuses on observations of molecular lines (from carbon monoxide-CO-and other species), and briefly at the end, on hydrogen radio recombination lines from the emerging H ii regions at the center of yPNe. The main goal of this contribution is to show the potential of (sub)mm-wavelength observations of pPNe/yPNe to help the community to devise and develop new observational projects that will bring us closer to a better understanding of these latest stages of the evolution of low-to-intermediate (similar to 0.8-8 M circle dot) mass stars.