Astronomy & Astrophysics

Table 6: Critical densities, $N_{\rm cr}$ , of the observed forbidden lines for an electron temperature of $T_{\rm e} = 10^4$ K, and total ionization energies, $\chi$ , for the production of the respective ion (Cox 2000). The last line gives $D_0 = N_0/N_{\rm cr}$ for a density N₀ = 10¹¹ cm^-3 at $r = 1~{R}_{\star}$ .
ion [O I] [Fe II] [N II] [S III]

line $\lambda6300$ Å $\lambda 7155$ Å $\lambda6583$ Å $\lambda 6312$ Å

$N_{\rm cr}~$ [cm^-3] $3\times 10^6$ $2.2\times 10^8$ $8.6\times 10^4$ $1.4\times 10^7$

$\chi$ [eV] 0.0 7.90 14.53 33.70

D₀ $3.3\times 10^4$ $4.5\times 10^2$ $1.2\times 10^6$ $7.1\times 10^3$

**Table 6:** Critical densities, $N_{\rm cr}$ , of the observed forbidden lines for an electron temperature of $T_{\rm e} = 10^4$ K, and total ionization energies, $\chi$ , for the production of the respective ion (Cox 2000). The last line gives $D_0 = N_0/N_{\rm cr}$ for a density N₀ = 10¹¹ cm^-3 at $r = 1~{R}_{\star}$ .
ion	[O I]	[Fe II]	[N II]	[S III]
line	$\lambda6300$ Å	$\lambda 7155$ Å	$\lambda6583$ Å	$\lambda 6312$ Å
$N_{\rm cr}~$ [cm^-3]	$3\times 10^6$	$2.2\times 10^8$	$8.6\times 10^4$	$1.4\times 10^7$
$\chi$ [eV]	0.0	7.90	14.53	33.70
D₀	$3.3\times 10^4$	$4.5\times 10^2$	$1.2\times 10^6$	$7.1\times 10^3$

Source LaTeX | All tables | In the text