2021MNRAS.505.3635M

We present here results from a survey of intervening C IV absorbers at z < 0.16 conducted using 223 sightlines from the Hubble Spectroscopic Legacy Archive. Most systems (83%) out of the total sample of 69 have simple kinematics with 1 or 2 C IV components. In the 22 C IV systems with well constrained H I column densities, the temperatures from the b-values imply predominantly photoionized plasma (T <= 10⁵ K) and non-thermal dynamics. These systems also have solar or higher metallicities. We obtain a C IV line density of d N/ dX = 5.1±1.0 for log[N( C iv)~( cm^–2)]≥12.9, and Ω_ C iv_=(8.01±1.62) ×10^–8 for 12.9 ≤log[N( C iv)~( cm^–2)] ≤15.0. The C IV bearing diffuse gas in the z < 0.16 Universe has a metallicity of (2.07 ± 0.43) x 10^–3 Z_☉, an order of magnitude more than the metal abundances in the IGM at high redshifts (z >= 5), and consistent with the slow build-up of metals in the diffuse circum/intergalactic space with cosmic time. For z < 0.015 (complete above L > 0.01L^*), the Sloan Digital Sky Survey provides a tentative evidence of declining covering fraction for strong C IV (N > 10^13.5 cm^–2) with ρ (impact parameter) and ρ/R_vir. However, the increase at high separations suggests that strong systems are not necessarily coincident with such galaxies. We also find that strong C IV absorption at z < 0.051 is not coincident with galaxy overdense regions complete for L > 0.13L^*.