TY  - JOUR
A1  - Shenar, Tomer
A1  - Oskinova, Lida
A1  - Hamann, Wolf-Rainer
A1  - Corcoran, Michael F.
A1  - Moffat, Anthony F. J.
A1  - Pablo, Herbert
A1  - Richardson, Noel D.
A1  - Waldron, Wayne L.
A1  - Huenemoerder, David P.
A1  - Maiz Apellaniz, Jesus
A1  - Nichols, Joy S.
A1  - Todt, Helge Tobias
A1  - Naze, Yael
A1  - Hoffman, Jennifer L.
A1  - Pollock, Andy M. T.
A1  - Negueruela, Ignacio
T1  - A coordinated X-Ray and optical campaign of the nearest massive eclipsing binary, delta ORIONIS Aa. IV. A multiwavelength, non-lte spectroscopic analysis
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Eclipsing systems of massive stars allow one to explore the properties of their components in great detail. We perform a multi-wavelength, non-LTE analysis of the three components of the massive multiple system delta Ori A, focusing on the fundamental stellar properties, stellar winds, and X-ray characteristics of the system. The primary's distance-independent parameters turn out to be characteristic for its spectral type (O9.5 II), but usage of the Hipparcos parallax yields surprisingly low values for the mass, radius, and luminosity. Consistent values follow only if delta Ori lies at about twice the Hipparcos distance, in the vicinity of the sigma-Orionis cluster. The primary and tertiary dominate the spectrum and leave the secondary only marginally detectable. We estimate the V-band magnitude difference between primary and secondary to be Delta V approximate to 2.(m)8. The inferred parameters suggest that the secondary is an early B-type dwarf (approximate to B1 V), while the tertiary is an early B-type subgiant (approximate to B0 IV). We find evidence for rapid turbulent velocities (similar to 200 km s(-1)) and wind inhomogeneities, partially optically thick, in the primary's wind. The bulk of the X-ray emission likely emerges from the primary's stellar wind (logL(X)/L-Bol approximate to -6.85), initiating close to the stellar surface at R-0 similar to 1.1 R-*. Accounting for clumping, the mass-loss rate of the primary is found to be log (M) over dot approximate to -6.4 (M-circle dot yr(-1))., which agrees with hydrodynamic predictions, and provides a consistent picture along the X-ray, UV, optical, and radio spectral domains.
KW  - binaries: close
KW  - binaries: eclipsing
KW  - stars: early-type
KW  - stars: individual ([HD 36486]delta Ori A)
KW  - X-rays: stars
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/809/2/135
SN  - 0004-637X
SN  - 1538-4357
VL  - 809
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -