4.3 Ionized Absorption Lines

Strong absorption lines of key H- and He-like ions were visually identified initially, and we modeled them using a series of Gaussian absorption functions (gabs ) with physical properties listed in Table 3. For thoroughness, we also identified additional potential spectral features using a blind line search described in the Appendix. For these key lines, we obtained the ionic column densities ($N_{j}$) from the following relationship between $W_{\lambda}$ and $N_{j}f_{jk}$ for the unsaturated absorption lines (Spitzer, 1978, Ch. 3):

$$\frac{W_{\lambda}}{\lambda}=\frac{\pi e^2}{m_e c^2} N_{j} \lambda f_{jk},\\$$ (3)

where $W_{\lambda}$ is the line equivalent width, $\lambda$ the wavelength, $N_{j}$ the ionic column density, $f_{jk}$ the oscillator strength of the relevant transition taken from the atomic database AtomDB (v.2.0.2; Foster et al., 2012), $c$ the speed of light, $m_e$ the electron mass, and $e$ the elementary charge.

Table 3 lists the measured outflow velocity ( $v_{\rm out}$). and the line equivalent width ( $W_{\lambda}$) in mÅ from the absorption lines. The turbulent velocity width is estimated from the FWHM ( $=2\sqrt{2\ln 2} \sigma$, where $\sigma$ is the velocity dispersion) of the line profile using $v_{\rm turb}={\rm FWHM}/2 \sqrt{\ln 2}$. The ionic column density is derived using equation (3).