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arXiv · 2412.12302

The CIViL* Survey: The Discovery of a C IV Dichotomy in the CGM of L* Galaxies

Samantha L. Garza·Jessica K. Werk·Trystyn A. M. Berg·Yakov Faerman·Benjamin D. Oppenheimer·Rongmon Bordoloi·Sara L. Ellison
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Abstract

This paper investigates C IV absorption in the circumgalactic medium (CGM) of L* galaxies and its relationship with galaxy star formation rates. We present new observations from the C IV in L* survey (CIViL*; PID$\#$17076) using the Hubble Space Telescope/Cosmic Origins Spectrograph. By combining these measurements with archival C IV data (46 observations total), we estimate detection fractions for star-forming (sSFR $>$ 10$^{-11}$ yr$^{-1}$) and passive galaxies (sSFR $\leq$ 10$^{-11}$ yr$^{-1}$) to be 72$_{-18}^{+14}$\% [21/29] and 23$_{-15}^{+27}$\% [3/13], respectively. This indicates a significant dichotomy in C IV presence between L* star-forming and passive galaxies, with over 99% confidence. This finding aligns with Tumlinson et al. (2011), which noted a similar dichotomy in O VI absorption. Our results imply a substantial carbon reservoir in the CGM of L* galaxies, suggesting a minimum carbon mass of $\gtrsim$ 3.03 $\times$ 10$^{6}$ M$_{\odot}$ out to 120 kpc. Together, these findings highlight a strong connection between star formation in galaxies and the state of their CGM, providing insight into the mechanisms governing galaxy evolution.

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Samantha L. Garza, Jessica K. Werk, Trystyn A. M. Berg, Yakov Faerman, Benjamin D. Oppenheimer, Rongmon Bordoloi, Sara L. Ellison. 2024-12-16. The CIViL* Survey: The Discovery of a C IV Dichotomy in the CGM of L* Galaxies. https://doi.org/10.3847/2041-8213%2Fad9c69c

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