Universality of the companion mass-ratio distribution
Institute of Astronomy, ETH Zurich, 8093 Zurich, Switzerland
Received: 3 April 2013
Accepted: 12 April 2013
Aims. We present new results regarding the companion mass-ratio distribution (CMRD) of stars, as a follow-up of our previous work.
Methods. We used a maximum-likelihood-estimation method to re-derive the field CMRD power law avoiding dependence on the arbitrary binning. We also considered two new surveys of multiples in the field for solar-type stars and M dwarfs to test the universality of the CMRD.
Results. We found no significant differences in the CMRD for M dwarfs and solar-type stars compared with previous results over the common mass ratio and separation range. The new best-fit power law of the CMRD in the field, combining two previous sets of data, is dN/dq ∝ qβ, with β = 0.25 ± 0.29.
Key words: binaries: general / stars: formation / stars: low-mass / stars: solar-type
© ESO, 2013