the ratio of measured to theoretical EWs for each of the feature identified and included in building of the spectrum, given by the LIP, with IW, $\Delta \lambda = 10^{-4}$ Å.

This plot infers that the plasma gas density reproducing best the observation is $n_H=10^{12}$ , where SD=0.0. Fitting procedures allow us to set limits on SD in order to achieve confidence level in therms of $\chi^2$. SD of 0.12-0.15 produce changes $> 90$ % confidence level on measurements of $n_H$. We are able to infer the gas density of the spectrum to be $n_H=(2.4\times 10^{10}, 1.2\times 10^{13})$ , for the LIP component of the absorbing complex in model B.

The COG ratio shown by the MIP is an excellent case of highly sensitive curve with $n_H$ (see Figure \[den\_dist2\]). The envolvent (irregular gray polygon) makes a strong constrain of the gas density to be $n_H\approx 10^{12}$ . Again limits on the measurements using SD=0.15-0.17 ($\chi^2 > 2.79$) reports $n_H=(1.9\times 10^{10}, 3.1\times 10^{12})$ , for the MIP component of model B.

We checked for the robustness of these measurements with the building of a 2D contours, produced by computing a grid of photoionization models for wabs1 (MIP) and wabs2 (LIP), 