Table 1: Atomic and molecular parameters of the observed spectral lines. $\lambda _0$ represents the laboratory central wavelength, $\chi _{\rm l}$ the excitation potential of the lower energy level, and $\log gf$ the logarithm of the oscillator strength times the multiplicity of the level. The parameters $\alpha$ and $\sigma$ (in units of Bohr's radius, a₀) are used to calculate the broadening of the lines by collisions with neutral hydrogen atoms as resulting from the ABO theory (Barklem & O'Mara 1997). The last column gives the effective Landé factor of the transition, $g_{\rm eff}$ . For the molecular lines $I_{\rm U}$ , $I_{\rm L}$ , $V_{\rm U}$ and $V_{\rm L}$ represent the upper/low multiplets sublevels and vibrational levels respectively. $J_{\rm L}$ stands for the rotational number of the lower level. Finally, the oscillator strength of the molecular transition is given.
Atom $\lambda _0$ $\chi_{l}$ log gf $\alpha$ $\sigma$ $g_{\rm eff}$

(Å ) (eV) (dex) (a₀²)

Fe I 15 648.515 5.426 -0.675 0.229 977 3.00

Fe I 15 652.874 6.246 -0.043 0.330 1444 1.53

Molecule $\lambda _0$ Branch $I_{\rm U}-I_{\rm L}$ $V_{\rm U}-V_{\rm L}$ $J_{\rm L}$ f

OH 15 651.895 P 1-1 3-1 6.5 $0.8 \times10^{-6}$

OH 15 653.478 P 1-1 3-1 6.5 $0.8 \times10^{-6}$

**Table 1:** Atomic and molecular parameters of the observed spectral lines. $\lambda _0$ represents the laboratory central wavelength, $\chi _{\rm l}$ the excitation potential of the lower energy level, and $\log gf$ the logarithm of the oscillator strength times the multiplicity of the level. The parameters $\alpha$ and $\sigma$ (in units of Bohr's radius, a₀) are used to calculate the broadening of the lines by collisions with neutral hydrogen atoms as resulting from the ABO theory (Barklem & O'Mara 1997). The last column gives the effective Landé factor of the transition, $g_{\rm eff}$ . For the molecular lines $I_{\rm U}$ , $I_{\rm L}$ , $V_{\rm U}$ and $V_{\rm L}$ represent the upper/low multiplets sublevels and vibrational levels respectively. $J_{\rm L}$ stands for the rotational number of the lower level. Finally, the oscillator strength of the molecular transition is given.
Atom	$\lambda _0$	$\chi_{l}$	log gf	$\alpha$	$\sigma$	$g_{\rm eff}$
	(Å )	(eV)	(dex)		(a₀²)
Fe I	15 648.515	5.426	-0.675	0.229	977	3.00
Fe I	15 652.874	6.246	-0.043	0.330	1444	1.53
Molecule	$\lambda _0$	Branch	$I_{\rm U}-I_{\rm L}$	$V_{\rm U}-V_{\rm L}$	$J_{\rm L}$	f
OH	15 651.895	P	1-1	3-1	6.5	$0.8 \times10^{-6}$
OH	15 653.478	P	1-1	3-1	6.5	$0.8 \times10^{-6}$

Source LaTeX | All tables | In the text

	1 Introduction
	2 Description of the penumbral model and Stokes profile inversion
	3 Observations and data reduction
	4 Results and discussion
	5 Width of the penumbral filaments and Stokes V area asymmetry
	6 Nature of the Evershed flow
	7 Summary and conclusions
	References