On the nitrogen abundance of FLIERs: the outer knots of the planetary nebula NGC 7009

Denise R. Goncalves, ; Barbara Ercolano, ; A. Carnero +2

We have constructed a 3D photoionisation model of a planetary nebula (PN) similar in structure to NGC 7009 with its outer pair of knots (also known as FLIERs --fast, low-ionization…