大样本恒星演化研究组知识库

Binary interactions play an important role in the formation and shaping of planetary nebulae. In this paper, different evolutionary channels of binary stars and their Importance in the formation of bipolar planetary nebulae are investigated. Using a Monte-Carlo technique, we explore the consequences of different mass-ratio distributions, different initial-final mass relations as well as different theoretical assumptions concerning the modelling of the common-envelope phase. We have come to the following conclusions: (1) The morphology of 34% to 43% of all PNe's may be affected by binary interactions; (2) The main types of binary interactions considered (gravitational, focussing, common-envelope ejection and binary merger) are of comparable importances; (3) Massive binaries are slightly more likely to produce bipolar PNe, provided that the initial mass-ratio distribution is biased towards a mass ratio near unify; (4) The ejection of the common envelope may be very efficient; (5) Our simulations support the initial-final mass relation proposed by Han, Podsiadlowski and Eggleton and the use of PNe as a standard distance candle.