G. Israelian, EXTENDED WINGS OF THE UV SI-IV, C-IV RESONANCE DOUBLETS AND THE COMPLEX [FE-II] PROFILES IN P-CYGNI, Astronomy and astrophysics, 300(3), 1995, pp. 834-842
We investigate the formation and the nature of the extended wings of t
he UV resonance lines of Si IV 1394, 1402 Angstrom and C IV 1548 and 1
550 Angstrom in the spectrum of the LBV P Cyg. The effects of line ble
nding in the neighbourhood of these lines were estimated by means of a
grid of theoretical synthetic spectra, computed for the P Cyg model a
tmosphere. It is shown that line blending is responsible for the stron
g wings of these lines with photospheric origin.Our models are next us
ed to treat the problem of the complex structure of [Fe II] lines obse
rved by Stahl et al. in the optical spectra of P Cygni. We find that a
bsorption, emission and P Cygni-type lines blending with the [Fe II] l
ines are responsible for their complex structure. This offers an examp
le of how line blending can be wrongly interpreted as evidence for blo
bs in a stellar wind.