Physical Properties, Abundances and Photoionization Modeling of 12 Galactic PNe

In this study, we present the results of an investigation of the the physical properties, abundances, and photoionization modeling of planetary nebula (PN) candidates from the HASH database having small angular sizes (<8'' with one exception) and located in the Northern sky hemisphere. We collected new spectroscopic data of these objects. We confirmed 12 PNe using diagnostic diagrams, emission line ratios and calculated their physical conditions such as extinction coefficient, electron density, and electron temperature. We conducted elemental abundance calculations for the PNe and found that their abundances align with both solar and Galactic values. Additionally, utilizing photoionization models developed with the Cloudy code, we obtained the effective temperatures of central stars, which span from 40 000 K to 250 000 K, along with luminosities ranging from 400 L⊙ to 10 000 L⊙. We determined the initial mass values of the PNe to be in the 0.8-4.5 M⊙ range on the HR diagram with post-AGB evolutionary tracks using their Teff and luminosity values. Considering the final masses of these PNe, their mass losses were estimated to be approximately between 0.3 M⊙ and 3.6 M⊙. Notably, we found that the ages of the PNe, determined from post-AGB evolutionary tracks, varied from 120 to 34 000 yr, consistently with the earlier findings.