Analysis of Planetary Nebulae in the Milky Way: Physical Properties, Chemical Abundances, and Galactic Distributions

Abstract

In this study, we investigate the physical and chemical properties of planetary nebulae (PNe) from the Milky Way Galaxy using the largest number of sources to date, with 1,449 True PNe from the HASH database. Among the Galactic components thin disk, thick disk, halo, and bulge-most PNe are concentrated in the Galactic disk, with a median angular size of 12 arcseconds (0.45 pc), while halo PNe tend to have larger sizes. Physical parameters of whole PNe, extinction coefficent c(Hbeta), electron temperature (Te), and density (Ne) show Gaussian-like distributions with medians of 1.5, 9,900 K, and 1,200 cm(-3), respectively. The abundances of He, N, O, Ne, S, Cl, and Ar in PNe show Gaussian distributions with slight variations across Galactic components. PNe located in thin disk exhibit higher abundances, except for O and Ne, while PNe in halo have the lowest values for all elements. Strong correlations between elements, particularly Sulphur vs. Nitrogen (r=0.87), were identified using statistical tests. Comparisons with previous studies reveal variations ( 2 dex.) in abundance ratios, particularly in halo PNe. We also present the first detailed database in the literature, providing 7,200 abundance values for these elements, derived from 16,500 emission line measurements, to support the testing and development of theoretical models.