DIISC -- VI (COS-DIISC): UV Metal Absorption Relative to the H I disk of Galaxies

• DOI: 10.48550/arxiv.2502.02583
• Publication Date: 2025-02-04
• Authors: Brad Koplitz; Sanchayeeta Borth...; T. Heckman; Mansi Padave; Tyler McCabe; Jason Tumlinson; Andrew J. Fox; Guinevere Kauffmann
• Keywords: Astrophysics of Galaxies (astro-ph.GA); FOS: Physical sciences; Astrophysics - Astrophysics of Galaxies

As part of the Deciphering Interplay between Interstellar medium, Stars, and Circumgalactic medium (DIISC) survey, we present UV metal absorption features in Medium (CGM) near H I gas disk ($<$4.5$R_\mathrm{HI}$) 31 nearby galaxies through quasar line spectroscopy. Of ions under study, Si III $\lambda1206$ was most frequently detected (18 sight lines), while C II $\lambda1334$ $\lambda1260$ were 17 15 lines, respectively. Many components consistent with photoionization equilibrium models, cold cool phase clouds found to have lengths smaller than 2 kpc. Sight lines impact parameters ($\rho$) normalized by galaxy's virial radius ($R_\mathrm{vir}$) ($R_\mathrm{HI}$) tend more larger rest-frame equivalent widths ($W_r$) those that probe CGM at radii. In particular, find location metals are better traced $\rho$ / $R_\mathrm{HI}$ rather traditional $R_\mathrm{vir}$. Larger covering fractions closer galaxies, a radial decline depends on $W_r$ limit used. Our results provide new insights into spatial distribution around disks low-redshift galaxies.