Planetary Nebulae: results of abs spectroscopy

Based on these data, fundamental physical parameters were calculated, including sizes, densities, electron temperatures, and central star characteristics. The table includes:

• Object identifiers, excitation classes, and interstellar extinction at Hβ.
• Morphological and distance properties: angular diameters (Diam_arcsec), linear sizes (Diam_pc), and heliocentric distances (D_kpc).
• Electron densities from [SII] 6717/6731 ratios.
• Effective temperatures of central stars estimated both by the Zanstra method (T_HI) and empirical [OIII]-based calibrations (T0_[OIII], T1_[OIII]), given in units of 10**4 K.
• Timescales: duration of available observations (delta_t_obs_year) and model reproduction intervals (delta_t_model_year), linked to evolutionary models by Bertolami (2016, A&A 588, A25).
• Absolute emission-line fluxes for Hβ, HeII 4685, [OIII] 5007, Hα, [NII] 6583, HeI 6678, [SII] 6717/6731, HeI 7065, [ArIII] 7136, and [OI] 7324, with measurement uncertainties and (where relevant) a power-of-ten exponent. Each measurement is provided in a machine-readable format, separating values, uncertainties, and exponents into dedicated columns. This ensures precise numerical handling and interoperability with Virtual Observatory services and pipelines.