Spectroscopy and Photoionization Model of Planetary Nebulae: NGC 6543 and NGC 7662

Abstract

Spectroscopic observations in the wavelength range of λλ4000 — 8000 Å of the planetary nebulae (PN), NGC 6543 and NGC 7662, have been undertaken in 2014 using the compact spectrograph attached to the 28-cm Schmidt-Cassegrainian reflector at Koyama Astronomical Observatory. We derived physical parameters of NGC 6543 and NGC 7662 from the analyses of observed emission lines, i.e. electron temperature, density, and elemental abundances. To obtain more reliable physical quantities of NGC 6543 and NGC 7662, the use of photoionization model is needed. We use the computer code, CLOUDY C13.3 to build detailed photoionization models of NGC 6543 and NGC 7662. Model of NGC 6543 and 7662 can be constructed by providing sufficient information on physical parameters of the central stars and the nebula. In this work, input parameters to construct the photoionization model of NGC 6543 and NGC 7662 are distance, temperature and luminosity of central star and nebula parameters. The model results were compared with observational result taken in 2014. Observed and modeled temperatures were deduced from [O III] λλ(4959 + 5007) Å /λ4636 Å and the electron density from [S II] λλ 6716/6731 Å. There are some discrepancies between observed and modeled due to limitations inherent with the resolution and quality of spectroscopic data. Further spectroscopic observations with higher resolution of NGC 6543 and NGC 7662 is recommended.