H I absorption feature of UGC 00613. The solid blue line depicts the absorption spectrum, and the solid red line shows the fit with a double-component Gaussian model (components shown as orange and green dashed lines). The magenta dot-dashed vertical line marks the redshift of UGC 00613 as given in the NASA/IPAC Extragalactic Database. The fitting residual is shown as the solid black line at the bottom. The optical depth value for the H I absorption is shown on the right scale.