SRON Laboratory for Space Research, PO Box 800, NL 9700 AV Groningen, The Netherlands
2 Kapteyn Astronomical Institute, PO Box 800, NL 9700 AV Groningen, The Netherlands
3 Laboratory for Astronomy and Solar Physics, NASA–Goddard Space Flight Center, Greenbelt, MA 20771, USA
Corresponding author: J. Bernard Salas, J.Bernard@sron.rug.nl
Accepted: 5 March 2002
The infrared and ultraviolet spectra of planetary nebula NGC 2440 are presented. The observations were made by the Infrared Space Observatory (ISO) and the International Ultraviolet Explorer (IUE). These data, in conjunction with published optical observations have been used to derive electron temperature and density. The electron temperature increases with increasing ionization potential, from 11 000 to 18 000 K. The electron density has a constant value of 4500 cm-3 in agreement with previous determinations. The chemical abundance has been derived for the following elements; helium, carbon, nitrogen, oxygen, neon, sulfur and argon. The ionization correction factor turns out to be very small for all species except sulfur.
Key words: ISM: abundances / planetary nebulae: individual: NGC 2440 / infrared: ISM / ISM: lines and bands
© ESO, 2002