大样本恒星演化研究组知识库

We have carried out a detailed study of symbiotic stars (SySs) with white dwarf (WD) accretors by means of a population synthesis code. We estimate the total number of SySs with WD accretors in the Galaxy as 1200-15 000. This range is compatible with observational estimates. Two crucial physical parameters that define the birth rate and number of SySs are the efficiency of accretion by WDs (which greatly depends on the separation of components after the common envelope stage and stellar wind velocity) and the mass of the hydrogen layer, which the WD can accumulate prior to hydrogen ignition. The theoretical estimate of the Galactic occurrence rate of symbiotic novae (SyNe) ranges from about 1.3 to about 13.5 yr(-1), out of which weak SyNe comprise about 0.5 to 6.0 yr(-1), depending on the model assumptions. We simulate the distributions of SySs over orbital periods, masses of components, mass-loss rates of cool components, mass-accretion rates of hot components and luminosity of components. The agreement with observations is reasonable.