2006/04/01 by R. B. C. Henry, J. N. Skinner, Julie N. Skinner +3 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1017/s1743921306003528
Two pages, two figures. Contributed paper, IAU Symp. 234, ``Planetary Nebulae in our Galaxy and Beyond.''
openalex publication_date 2006/04/01 · arxiv created 2006/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
The alpha elements O, Ne, Mg, Si, S, Cl, and Ar are produced together in massive stars and their abundances are expected to evolve in lockstep. Both H II regions and planetary nebulae serve as interstellar probes of alpha element abundances. We have measured abundances for the alpha elements O, Ne, S, Cl, and Ar in over 130 Galactic Types I and II and halo PNe in a consistent manner from our own optical (3600–9600Å) spectra (Henry, Kwitter, & Balick 2004). Figure 1 is a plot of Ne vs. O for a combined dataset containing H II regions, blue compact galaxies, and our sample of planetary nebulae. All object types appear to be consistent with the expected linear relation between Ne and O. Similar plots of Cl and Ar vs. O show the same behavior. However, S vs. O is an exception.