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):

$\displaystyle \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).

Ashkbiz Danehkar