Table 2: RGS fitting results for the oxygen region in Cyg X-2. The parameters for the continuum emission are taken from the broad-band spectrum. The energies are measured in keV and the Equivalent Width ( EW) in eV. Model 1 fits the O vicinity with 3 edges (two of which are from atomic O) and 2 absorption lines (one from atomic neutral O and the other from molecular O). Model 2 interprets the spectrum in terms of absorption by atomic O, either neutral or mildly ionized. Errors are given at 90% confidence for one interesting parameter.
model 1 model 2

Lines

E₁ $0.524\pm0.003$ $0.524\pm0.003$

${\it EW}_1$ 1.45 ^+0.22_-0.14 $1.49\pm0.17$

E₂ $0.530\pm0.001$ $0.530\pm0.001$

${\it EW}_2$ $1.41\pm0.26$ $1.44\pm0.28$

E₃ $\cdots$ $0.538\pm0.001$

${\it EW}_3$ $\cdots$ 0.44^+0.19_-0.24

E₄ $\cdots$ $0.541\pm0.001$

${\it EW}_4$ $\cdots$ 1.01 ^+0.15_-0.26

Edges

E₁ 0.536 fix. $\cdots$

$\tau_1$ $0.27\pm0.06$ $\cdots$

E₂ 0.543 fix. $0.543\pm0.001$

$\tau_2$ $0.45\pm0.02$ $0.81\pm0.02$

E₃ 0.549 fix. $\cdots$

$\tau_3$ 0.09 ^+0.07_-0.08 $\cdots$

**Table 2:** RGS fitting results for the oxygen region in Cyg X-2. The parameters for the continuum emission are taken from the broad-band spectrum. The energies are measured in keV and the Equivalent Width ( EW) in eV. Model 1 fits the O vicinity with 3 edges (two of which are from atomic O) and 2 absorption lines (one from atomic neutral O and the other from molecular O). Model 2 interprets the spectrum in terms of absorption by atomic O, either neutral or mildly ionized. Errors are given at 90% confidence for one interesting parameter.
	model 1	model 2
Lines
E₁	$0.524\pm0.003$	$0.524\pm0.003$
${\it EW}_1$	1.45 ^+0.22_-0.14	$1.49\pm0.17$
E₂	$0.530\pm0.001$	$0.530\pm0.001$
${\it EW}_2$	$1.41\pm0.26$	$1.44\pm0.28$
E₃	$\cdots$	$0.538\pm0.001$
${\it EW}_3$	$\cdots$	0.44^+0.19_-0.24
E₄	$\cdots$	$0.541\pm0.001$
${\it EW}_4$	$\cdots$	1.01 ^+0.15_-0.26
Edges
E₁	0.536 fix.	$\cdots$
$\tau_1$	$0.27\pm0.06$	$\cdots$
E₂	0.543 fix.	$0.543\pm0.001$
$\tau_2$	$0.45\pm0.02$	$0.81\pm0.02$
E₃	0.549 fix.	$\cdots$
$\tau_3$	0.09 ^+0.07_-0.08	$\cdots$

Source LaTeX | All tables | In the text

	1 Introduction
	2 The halo theory
	3 Data analysis
	4 The analysis of the scattering halo
	5 The halo modeling
	6 Discussion
	7 Conclusions
	References