Spectral Analysis of Central Stars of Planetary Nebulae

TL;DR

This paper discusses advanced spectral analysis of central stars of planetary nebulae using NLTE models, demonstrating detailed property determination and providing tools for synthetic spectra generation to aid nebula analysis.

Contribution

It presents state-of-the-art NLTE model atmospheres for central stars, detailed spectral analysis of LSV +4621, and accessible tools for synthetic spectra generation within the GAVO framework.

Findings

Accurate determination of stellar parameters like temperature and abundances.

Reliable prediction of ionizing spectra for nebula analysis.

Provision of synthetic spectra tools for the community.

Abstract

Spectral analysis by means of NLTE model atmospheres has presently arrived at a high level of sophistication. High-resolution spectra of central stars of planetary nebulae can be reproduced in detail from the infrared to the X-ray wavelength range. In the case of LSV +4621, the exciting star of Sh 2-216, we demonstrate the state-of-the-art in the determination of photospheric properties like, e.g., effective temperature, surface gravity, and abundances of elements from hydrogen to nickel. From such detailed model atmospheres, we can reliably predict the ionizing spectrum of a central star which is a necessary input for the precise analysis of its ambient nebula. NLTE model-atmosphere spectra, however, are not only accessible for specialists. In the framework of the German Astrophysical Virtual Observatory (GAVO), we provide pre-calculated grids of tables with synthetic spectra of hot, compact stars as well as a tool to calculate individual model-atmosphere spectra in order to make the use of synthetic stellar spectra as easy as the use of blackbody flux distributions had been in the last century.