Bibcode
Simón-Díaz, S.; Caballero, J. A.; Lorenzo, J.; Maíz Apellániz, J.; Schneider, F. R. N.; Negueruela, I.; Barbá, R. H.; Dorda, R.; Marco, A.; Montes, D.; Pellerin, A.; Sanchez-Bermudez, J.; Sódor, Á.; Sota, A.
Referencia bibliográfica
The Astrophysical Journal, Volume 799, Issue 2, article id. 169, 12 pp. (2015).
Fecha de publicación:
2
2015
Revista
Número de citas
44
Número de citas referidas
40
Descripción
We provide a complete characterization of the astrophysical properties
of the σ Ori Aa, Ab, B hierarchical triple system and an improved
set of orbital parameters for the highly eccentric σ Ori Aa, Ab
spectroscopic binary. We compiled a spectroscopic data set comprising 90
high-resolution spectra covering a total time span of 1963 days. We
applied the Lehman-Filhés method for a detailed orbital analysis
of the radial velocity curves and performed a combined quantitative
spectroscopic analysis of the σ Ori Aa, Ab, B system by means of
the stellar atmosphere code FASTWIND. We used our own plus other
available information on photometry and distance to the system for
measuring the radii, luminosities, and spectroscopic masses of the three
components. We also inferred evolutionary masses and stellar ages using
the Bayesian code BONNSAI. The orbital analysis of the new radial
velocity curves led to a very accurate orbital solution of the σ
Ori Aa, Ab pair. We provided indirect arguments indicating that σ
Ori B is a fast-rotating early B dwarf. The FASTWIND+BONNSAI analysis
showed that the Aa, Ab pair contains the hottest and most massive
components of the triple system while σ Ori B is a bit cooler and
less massive. The derived stellar ages of the inner pair are
intriguingly younger than the one widely accepted for the σ
Orionis cluster, at 3 ± 1 Ma. The outcome of this study will be
of key importance for a precise determination of the distance to the
σ Orionis cluster, the interpretation of the strong X-ray emission
detected for σ Ori Aa, Ab, B, and the investigation of the
formation and evolution of multiple massive stellar systems and
substellar objects.
Proyectos relacionados
Proyecto IACOB: Una Nueva Era en el Estudio de Estrellas OB Galácticas
Massive stars has been many times claimed as Cosmic Engines and Gifts of Nature for the study of the Universe, from the Solar neighbourhood to the large-z Universe. The complete understanding of the physical properties and evolution of massive stars (and their interplay with the ISM) is crucial for many fields of Astrophysics and, ultimately, to
Sergio
Simón Díaz