Open AccessAn analysis of v sin ( i ) correlations in early‐type binaries
Author(s) -
Howe K. S.,
Clarke C. J.
Publication year - 2009
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2008.14073.x
Subject(s) - physics , astrophysics , radius , binary number , spin (aerodynamics) , orientation (vector space) , binary star , line (geometry) , stars , geometry , computer security , arithmetic , mathematics , computer science , thermodynamics
We use information on the v sin ( i ) values of early‐type binaries in order to search for correlations which may constrain the relative orientation of the stellar spin axes in binary systems. We find correlations in the case of close binaries which suggest that tidal synchronization is effective for binaries whose separation exceeds the stellar radius by more than an order of magnitude, in line with the theoretical predictions of Goldreich & Nicholson and the previous observational analysis of Giuricin et al. In the case of wide binaries, the v sin ( i ) values are not well correlated, which requires that the magnitude of the spin speeds is not tightly correlated. Under this assumption, we then find that the data provide no significant constraints on the degree of alignment of spin axes. The data are therefore compatible with scenarios (such as disc fragmentation or capture) which differ widely in the expected degree of spin alignment.