SATELLITE: Application to Planetary Nebulae IFU Data

Abstract

The integral field unit (IFU) spectroscopic view of extended ionized nebulae, such as planetary nebulae (PNe), H II regions, and galaxies, has changed the approach of studying these objects, providing a simultaneous characterization in both spatial directions. However, the spatial spaxel-by-spaxel analysis of such nebulae through IFUs is not directly comparable with the results obtained from the traditional slit-aperture spectroscopy or the predictions from 1D modelling. The new Python software called “satellite: Spectroscopic Analysis Tool for intEgraL fieLd unIt daTacubEs” is used in the analysis of the VIMOS and MUSE datacubes of four Galactic PNe. The 2D analysis of line ratio maps has shown important variations from one to another nebular component in NGC 7009 and NGC 6778. In particular, the knots in both PNe are characterized by strong emission from neutral gas that is weak or even absent from the main nebula, indicating significant variation in the ionization state and density structure among the nebular components. The far-UV radiation from the central star results in the photo-evaporation of the dense molecular knots resembling the spectrum of photodissociation regions.

Keywords

• integral field spectroscopy
• optical spectroscopy
• planetary nebulae
• data analysis