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DOE OSTI · 23159189

The Galactic Chemical Evolution of Chlorine

Maas, Z. G.
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Abstract

We measured {sup 35}Cl abundances in 52 M giants with metallicities in the range −0.5 < [Fe/H] < 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the NASA Infrared Telescope Facility and from optical echelle spectra. We measured Cl abundances by fitting a H{sup 35}Cl molecular feature at 3.6985 μm with synthetic spectra. We also measured the abundances of O, Ca, Ti, and Fe using atomic absorption lines. We find that the [Cl/Fe] ratio for our stars agrees with chemical evolution models of Cl, and the [Cl/Ca] ratio is broadly consistent with the solar ratio over our metallicity range. Both indicate that Cl is primarily made in core-collapse supernovae with some contributions from Type Ia supernovae. We suggest that other potential nucleosynthesis processes, such as the ν-process, are not significant producers of Cl. Finally, we also find our Cl abundances are consistent with H ii and planetary nebular abundances at a given oxygen abundance, although there is scatter in the data.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY79 ASTRONOMY AND ASTROPHYSICSABSORPTIONCHLORINECHLORINE 35INFRARED SPECTRAMETALLICITYNUCLEOSYNTHESISOXYGENSUPERNOVAETELESCOPES

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Maas, Z. G.. 2021-04-01. The Galactic Chemical Evolution of Chlorine. https://doi.org/10.3847/1538-3881%2Fabe38b

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