High-resolution spectroscopy of southern and equatorial Be stars: flux excess at λ4471 A.
BALLEREAU D., CHAUVILLE J. and ZOREC J.
Abstract (from CDS):
We present a catalogue of high-resolution He I 4471, Mg II 4481 and Hγ line profiles observed simultaneously for 37 southern and equatorial Be stars. In this paper we focus on the He I 4471 line, which is studied using non-LTE model line profiles. A systematic difference is found between the observed and the theoretical He I 4471 line equivalent widths. This difference strongly correlates with the Hγ emission and we interpret it as being due mainly to the veiling effect produced by the continuum emission excess originating in the circumstellar envelope. To determine the continuum flux excess we use two methods. One method enables us to obtain simultaneously the V sin i parameter. The flux excess we determined is overestimated by about 9% on average, because in the line profile analysis we neglected the gravity darkening effect due to stellar rotation. We find that 14 program stars present two possible solutions for V sin i. The second solution is, on average, 14% smaller and produces a small residual or emission-like difference between the observed He I 4471 line profile and the model profile.
line profile - stars: emission-line, Be - stars: atmosphere - atlases