Bibcode
Peña, M.; Ruiz-Escobedo, Francisco; Rechy-García, J.; García-Rojas, J.
Bibliographical reference
Planetary Nebulae: Multi-Wavelength Probes of Stellar and Galactic Evolution, Proceedings of the International Astronomical Union, IAU Symposium, Volume 323, pp. 60-64
Advertised on:
10
2017
Citations
4
Refereed citations
3
Description
In Planetary Nebulae (PNe) and HII regions ionic abundances can be
derived by using collisionally excited lines (CELs) or recombination
lines (ORLs). Such abundances do not coincide for the same ion and
usually abundances from ORLs are larger than those from CELs by factors
of 2 or larger. The origin of the discrepancy, known as the Abundance
Discrepancy Factor is an open problem in astrophysics of gaseous
nebulae. It has been attributed to temperature fluctuations in the
plasma, tiny metal-rich inclusions embedded in the H-rich plasma, gas
inhomogeneities or other processes. In this work we analyze the
kinematical behavior of CELs and ORLs in two PNe ionized by [WC] stars,
finding that kinematics of ORLS is incompatible with the kinematics of
CELs. In particular the expansion velocities from CELs and ORLs for the
same ion are different, indicating that ORLs seem to be produced in
zones nearer the central star than CELs. This is in agreement with
results found by other authors for individual PNe.