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Title: Massive binaries in the vicinity of Sgr A*

A long-term spectroscopic and photometric survey of the most luminous and massive stars in the vicinity of the supermassive black hole Sgr A* revealed two new binaries: a long-period Ofpe/WN9 binary, IRS 16NE, with a modest eccentricity of 0.3 and a period of 224 days, and an eclipsing Wolf-Rayet binary with a period of 2.3 days. Together with the already identified binary IRS 16SW, there are now three confirmed OB/WR binaries in the inner 0.2 pc of the Galactic center. Using radial velocity change upper limits, we were able to constrain the spectroscopic binary fraction in the Galactic center to F{sub SB}=0.30{sub −0.21}{sup +0.34} at a confidence level of 95%, a massive binary fraction close to that observed in dense clusters. The fraction of eclipsing binaries with photometric amplitudes Δm > 0.4 is F{sub EB}{sup GC}=3%±2%, which is consistent with local OB star clusters (F {sub EB} = 1%). Overall, the Galactic center binary fraction seems to be similar to the binary fraction in comparable young clusters.
Authors:
; ; ; ; ;  [1] ;  [2] ;  [3]
  1. Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching (Germany)
  2. Faculty of Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot 76100 (Israel)
  3. LUPM, Université Montpelier 2, CNRS, Place Eugéne Bataillon, F-34095, Montpellier (France)
Publication Date:
OSTI Identifier:
22351411
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 782; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; BINARY STARS; BLACK HOLES; COMPARATIVE EVALUATIONS; ECLIPSE; GALAXIES; GALAXY NUCLEI; PHOTOMETRY; RADIAL VELOCITY; SPECTROSCOPY; STAR CLUSTERS; STARS; WOLF-RAYET STARS