Twins like to be seen: Observational biases affecting spectroscopically selected binary stars
| Autor: | Cantrell, Andrew G., Dougan, Tyler J. |
|---|---|
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Mon.Not.Roy.Astron.Soc. 445 (2014) 2028-2033 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stu1890 |
| Popis: | Massive binary stars undergo qualitatively different evolution when the two components are similar in mass ('twins'), and the abundance of twin binaries is therefore important to understanding a wide range of astrophysical phenomena. We reconsider the results of Pinsonneault & Stanek (2006), who argue that a large proportion of binary stars have nearly equal-mass components; we find that their data imply a relatively small number of such 'twins.' We argue that samples of double-lined spectroscopic binaries are biased towards systems with nearly equal-brightness components. We present a Monte-Carlo model of this bias, which simultaneously explains the abundance of twins in the unevolved binaries of Pinsonneault & Stanek (2006), and the lack of twins in their evolved systems. After accounting for the bias, we find that their observed mass ratios may be consistent with a variety of intrinsic distributions, including either a flat distribution or a Salpeter distribution. We conclude that the observed overabundance of twins in Pinsonneault & Stanek (2006) does not reflect the true population of binaries, and we briefly discuss the astrophysical implications of the lack of twins. Comment: 7 pages, 4 figures; accepted for publication in Monthly Notices of the Royal Astronomical Society |
| Databáze: | arXiv |
| Externí odkaz: |
|