![]() | ![]() |
Astron. Astrophys. 338, 223-242 (1998) AcknowledgementsWe would like to thank the referee for critical comments which helped to improve the clarity of the paper. RL was supported by the Verbundforschung Astronomie/Astrophysik contract No. 50 OR 9414 9. ![]() ![]() ![]() ![]() © European Southern Observatory (ESO) 1998 Online publication: September 8, 1998 ![]() |