Far-Infrared Metallicity Diagnostics X-1

Elizabeth Fletcher

Ph.D. Candidate
Department of Physics
The Catholic University of America

Wed, December 4, 2024 ~ 4:00 PM

Gas-phase metallicity, defined as the abundance of heavy elements, provides crucial insights into the processes driving galaxy evolution and interactions. Metallicity is typically determined using optical emission lines, however we utilize far-infrared (FIR) fine-structure lines, which do not require corrections for dust extinction and are much less dependent on electron temperature.
These FIR metallicity diagnostics can be used with ALMA observations for high redshift galaxies and are especially applicable for nearby galaxies where dust extinction is an issue. Here I use archival spectroscopic data from SOFIA FIFI-LS and Herschel PACS to test FIR emission lines as metallicity diagnostics on local, star-forming, dwarf galaxies. In an accompanying study
I will analyze the neutral hydrogen gas in a small sample of nearby blue compact dwarf (BCD)
galaxies. Studying neutral hydrogen gas provides important insights into the distribution of gas,
its kinematics, and ongoing or past episodes of star formation. To investigate star formation
mode, I will use VLA data obtained from October 2022 to January 2023 which observed four
BCDs.

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