The Incidence of Stellar Mergers and Mass Gainers among Massive Stars
Abstract
Because the majority of massive stars are born as members of close binary systems, populations of massive main-sequence stars contain stellar mergers and products of binary mass transfer. We simulate populations of massive stars accounting for all major binary evolution effects based on the most recent binary parameter statistics and extensively evaluate the effect of model uncertainties. Assuming constant star formation, we find that 8^(+9)_(-4)% of a sample of early-type stars are the products of a merger resulting from a close binary system. In total we find that 30^(+10)_(-15)% of massive main-sequence stars are the products of binary interaction. We show that the commonly adopted approach to minimize the effects of binaries on an observed sample by excluding systems detected as binaries through radial velocity campaigns can be counterproductive. Systems with significant radial velocity variations are mostly pre-interaction systems. Excluding them substantially enhances the relative incidence of mergers and binary products in the non-radial velocity variable sample. This poses a challenge for testing single stellar evolutionary models. It also raises the question of whether certain peculiar classes of stars, such as magnetic O stars, are the result of binary interaction and it emphasizes the need to further study the effect of binarity on the diagnostics that are used to derive the fundamental properties (star-formation history, initial mass function, mass-to-light ratio) of stellar populations nearby and at high redshift.
Additional Information
© 2014 American Astronomical Society. Received 2013 October 4; accepted 2013 December 11; published 2014 January 20. We acknowledge various members of the VLT-FLAMES massive stars consortium, PI: C. Evans for stimulating discussions. S.d.M. acknowledges support for this work by NASA through an Einstein Fellowship grant, PF3-140105 and a Hubble Fellowship grant HST-HF-51270.01-A awarded by STScI, operated by AURA, Inc., for NASA, under contract NAS 5-26555.Attached Files
Published - 0004-637X_782_1_7.pdf
Submitted - 1312.3650v1.pdf
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Additional details
- Eprint ID
- 45003
- Resolver ID
- CaltechAUTHORS:20140417-095425292
- PF3-140105
- NASA Einstein Fellowship Program
- HST-HF-51270.01-A
- NASA Hubble Fellowship
- NAS 5-26555
- NASA
- Created
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2014-04-17Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field