Radial velocity measurements of white dwarfs

摘要: We present 594 radial velocity measurements for 71 white dwarfs obtained during our search binary and not reported elsewhere. identify three excellent candidate binaries, which require further observations to confirm preliminary estimates their orbital periods, one other good candidate. investigate whether data support the existence of a population single, low-mass (≲0.5 M⊙) (LMWDs). These stars are difficult explain using standard models stellar evolution. find that model with mixed single/binary is at least ~20 times more likely than pure population. This result depends on assumed period distributions LMWDs, companion masses several factors. Therefore, evidence in favour single LMWDs sufficient, opinion, firmly establish such population, but does suggest extended obtain convincing would be worthwhile.