Cosmic Origins
Searching for answers about our universe and its origins

Program News and Announcements

23 May 2023

Diffuse Gas in Cosmic Ecosystems Science Interest Group | Thursday, May 25th

Thursday, May 25, 2023 | 4:00pm EST (1:00pm PST)

Connection information and talk summary can be found at: Diffuse Gas SIG Colloquia

Far-Ultraviolet Spectra: The Key to Bridging Galaxy Evolution Across Cosmic Time

Speaker: Danielle Berg (UT Austin)

Rest-frame far-ultraviolet (FUV) spectra are fundamental to our understanding of star-forming galaxies, providing a unique window on massive stellar populations, chemical evolution, feedback processes, and reionization. The advent of the James Webb Space Telescope has opened our first window onto detailed abundance studies of high redshift (z > 6) galaxies. The coming years will provide the first spectroscopic samples of galaxies in the epoch of reionization with which we can constrain their chemical compositions and histories. The success of such endeavors hinges on a comprehensive understanding of the massive star populations and interstellar medium (ISM) gas conditions that power the observed FUV spectral features. I will present the COS Legacy Archive Spectroscopic SurveY (CLASSY) Treasury as a powerful and promising solution. The CLASSY atlas is the first high-quality, high-resolution FUV spectral catalog of star-forming galaxies at z~0. The spectra contain a suite of emission and absorption lines that simultaneously characterize the massive stellar populations that populate metal-poor galaxies, the physical properties of large-scale outflows that regulate star formation, and the chemical abundance patterns of the gas and stars. The CLASSY sample is consistent with the z∼0 mass-metallicity relationship, but is offset to higher star-formation rates by roughly 2 dex, similar to z~2 galaxies. This unique set of properties makes the CLASSY atlas the benchmark training set for studies of star-forming galaxies across cosmic time. While powerful, the CLASSY atlas is a small sample. I will, therefore, discuss the dire need for further FUV studies of nearby galaxies and their potential to help us unlock the mysteries encoded into the spectral signatures of the earliest galaxies.

Reach out to the Diffuse Gas In Cosmic Ecosystems SIG leaders if you have an interest in joining!

Diffuse Gas In Cosmic Ecosystems SIG

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