Ionization correction factors for sodium, potassium, and calcium in planetary nebulae

Amayo, A.; Delgado-Inglada, G.; García-Rojas, J.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society

Advertised on:
2
2020
Number of authors
3
IAC number of authors
1
Citations
7
Refereed citations
5
Description
We use a large grid of photoionization models that are representative of observed planetary nebulae (PNe) to derive ionization correction factors (ICFs) for sodium, potassium, and calcium. In addition to the analytical expressions of the ICFs, we provide the range of validity where the ICFs can be safely used and an estimate of the typical uncertainties associated with the ICFs. We improved the previous ICFs for calcium and potassium in the literature and suggest for the first time an ICF for sodium. We tested our ICFs with a sample of 39 PNe with emission lines of some ion of these elements. No obvious trend is found between the derived abundances and the degree of ionization, suggesting that our ICFs do not seem to be introducing an artificial bias in the results. The abundances found in the studied PNe range from -2.88_{-0.22}^{+0.21} to -2.09 ± 0.21 in log (Na/O), from -4.20_{-0.45}^{+0.31} to -3.05_{-0.47}^{+0.26} in log (K/O), and from -3.71_{-0.34}^{+0.41} to -1.57_{-0.47}^{+0.33} in log (Ca/O). These numbers imply that some of the studied PNe have up to ̃65 per cent, 75 per cent, or 95 per cent of their Na, K, and/or Ca atoms condensed into dust grains, respectively. As expected, the highest depletions are found for calcium which is the element with the highest condensation temperature.
Related projects
Izquierda - Imagen RGB de la nebulosa de Orión y M43 obtenida filtros estrechos con la cámara WFC en el INT: H alfa (rojo), [S II] 6716+30 (verde), [O III] 5007 (azul). Derecha - Imagen en falso color de la nebulosa planetaria NGC 6778. En azul se ve la emisión en la línea de O II tomada con el filtro sintonizable azul del instrumento OSIRIS en el GTC; en verde imagen con el filtro estrecho de [O III] del Nordic Optical Telescope (NOT).
Physics of Ionized Nebulae
The research that is being carried out by the group can be condensed into two main lines: 1) Study of the structure, dynamics, physical conditions and chemical evolution of Galactic and extragalactic ionized nebulae through detailed analysis and modelization of their spectra. Investigation of chemical composition gradients along the disk of our
Jorge
García Rojas