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Title: ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM

Abstract

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.more » 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.« less

Authors:
 [1]; ;  [2]; ; ; ;  [3];  [4];  [5];  [6];  [7]; ;  [8];  [9]
  1. Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain)
  2. Centro de Astrobiología (CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain)
  3. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Escuela Politécnica Superior, University of Alicante, Apdo. 99, E-03080 Alicante (Spain)
  4. Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany)
  5. Departamento de Física, Universidad de La Serena, Benavente 980, La Serena (Chile)
  6. Departamento Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)
  7. Department of Physics and Astronomy, State University of New York at Geneseo, 1 College Circle, Geneseo, NY 14454 (United States)
  8. Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, E-18008 Granada (Spain)
  9. Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, H-01121 Budapest (Hungary)
Publication Date:
OSTI Identifier:
22364374
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 799; 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; ASTROPHYSICS; B CODES; COMPUTERIZED SIMULATION; DIAGRAMS; EMISSION SPECTRA; F CODES; LUMINOSITY; MASS; MATHEMATICAL SOLUTIONS; PHOTOMETRY; RADIAL VELOCITY; STAR EVOLUTION; STARS; STELLAR ATMOSPHERES; X RADIATION

Citation Formats

Simón-Díaz, S., Caballero, J. A., Apellániz, J. Maíz, Lorenzo, J., Negueruela, I., Dorda, R., Marco, A., Schneider, F. R. N., Barbá, R. H., Montes, D., Pellerin, A., Sanchez-Bermudez, J., Sota, A., and Sódor, Á., E-mail: ssimon@iac.es. ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM. United States: N. p., 2015. Web. doi:10.1088/0004-637X/799/2/169.
Simón-Díaz, S., Caballero, J. A., Apellániz, J. Maíz, Lorenzo, J., Negueruela, I., Dorda, R., Marco, A., Schneider, F. R. N., Barbá, R. H., Montes, D., Pellerin, A., Sanchez-Bermudez, J., Sota, A., & Sódor, Á., E-mail: ssimon@iac.es. ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM. United States. doi:10.1088/0004-637X/799/2/169.
Simón-Díaz, S., Caballero, J. A., Apellániz, J. Maíz, Lorenzo, J., Negueruela, I., Dorda, R., Marco, A., Schneider, F. R. N., Barbá, R. H., Montes, D., Pellerin, A., Sanchez-Bermudez, J., Sota, A., and Sódor, Á., E-mail: ssimon@iac.es. Sun . "ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM". United States. doi:10.1088/0004-637X/799/2/169.
@article{osti_22364374,
title = {ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM},
author = {Simón-Díaz, S. and Caballero, J. A. and Apellániz, J. Maíz and Lorenzo, J. and Negueruela, I. and Dorda, R. and Marco, A. and Schneider, F. R. N. and Barbá, R. H. and Montes, D. and Pellerin, A. and Sanchez-Bermudez, J. and Sota, A. and Sódor, Á., E-mail: ssimon@iac.es},
abstractNote = {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.},
doi = {10.1088/0004-637X/799/2/169},
journal = {Astrophysical Journal},
number = 2,
volume = 799,
place = {United States},
year = {Sun Feb 01 00:00:00 EST 2015},
month = {Sun Feb 01 00:00:00 EST 2015}
}
  • High resolution Fourier-transform spectroscopy data of term values in the spin-orbit (SO) coupled first excited A {sup 1}Σ{sup +} and b{sup 3}Π{sub 0±} states in KCs were obtained from (4){sup 1}Σ{sup +} → A {sup 1}Σ{sup +} − b {sup 3}Π, A {sup 1}Σ{sup +} − b {sup 3}Π → X{sup 1}Σ{sup +}, and (1){sup 3}Δ{sub 1} → b{sup 3}Π{sub 0±} spectra of laser-induced fluorescence (LIF). About 3000 new rovibronic term values of the A {sup 1}Σ{sup +} and b {sup 3}Π{sub Ω} states were obtained with an uncertainty about 0.01 cm{sup −1} and added to the previously obtained 3439 term values in Kruzins et al. [Phys. Rev.more » A 81, 042509 (2010)] and 30 term values of the b {sup 3}Π{sub 0{sup +}} state levels below the A {sup 1}Σ{sup +} state in Tamanis et al. [Phys. Rev. A 82, 032506 (2010)]. The data field was extended considerably, going down to vibrational level v{sub b} = 0 and up in energy to 13 814 cm{sup −1}, as compared to previously achieved v{sub b} = 14 and E = 13 250 cm{sup −1}. Overall 6431 e-symmetry term values of {sup 39}K{sup 133}Cs were included in 4 × 4 coupled-channel deperturbation analysis. The analytical Morse-Long-Range (MLR) function yielded empirical diabatic potentials for the A {sup 1}Σ{sup +} and b {sup 3}Π{sub 0{sup +}} states while the morphing of the SO ab initio points [J. T. Kim et al., J. Mol. Spectrosc. 256, 57 (2009)] provided the empirical diagonal and off-diagonal SO functions. Overall 98.5% of the fitted term values were reproduced with a rms (root mean square) uncertainty of 0.004 cm{sup −1}. The reliability of the model is proved by a good agreement of predicted and measured term values of the {sup 41}K{sup 133}Cs isotopologue, as well as of measured and calculated intensities of (4){sup 1}Σ{sup +} → A {sup 1}Σ{sup +} − b {sup 3}Π LIF progressions. Direct-potential-fit of low-lying v{sub b} levels of the b {sup 3}Π{sub 0{sup −}} component yielded the MLR potential which represents the 204 f-symmetry experimental term values with a rms uncertainty of 0.002 cm{sup −1}. The Ω-doubling of the b {sup 3}Π{sub 0} sub-state demonstrates a pronounced v{sub b}-dependent increase.« less
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