The space frequency and origin of the runaway O and B stars

Abstract

Determinations of space frequency for runaway O and B stars are in very poor agreement, and many possible sources of systematic errors have been put forward. This paper investigates these sources, as well as others, and presents means for determining unbiased (true) space frequencies. When corrected for major sources of systematic error, space frequency determinations for the runaway O stars are in very good agreement but less so for the B-type runaways. The true space frequencies of runaway O and B stars are, respectively, 46 percent and 4 percent, as discussed in this paper. The former value is very supportive, along with other arguments presented in this paper, for runaway O stars being produced from supernova explosions in massive binaries. The origin of the B-type runaways is less clear.