A binary engine fuelling HD 87643's complex  
circumstellar environment

Millour, F.; Chesneau, O.; Fernandes, M. Borges; Meilland, A.; Mars, G.; Benoist, Christophe; Thiébaut, Éric; Stee, Philippe; Hofmann, K.-H.; Baron, Frédérique; Young, John S.; Bendjoya, Philippe; Carciofi, A. C.; Souza, A. Domiciano de; Driebe, T.; Jankov, S.; Kervella, P.; Petrov, R.; Robbe-Dubois, S.; Vakili, F.; Waters, L. B. F. M.; Weigelt, G.

doi:10.1051/0004-6361/200811592

Cited by 58 publications

(71 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other interesting objects in which a close (in projection) binary component was discovered by means of interferometry are the A[e] supergiant HD 62623 (Millour et al 2011, although this star was recently re-classified as a B8-9 Ib-II star by Borges Fernandes et al, in prep.) and the B[e]SG candidates HD 87643 (Millour et al 2009) and V921 Scorpii (=CD-42 11721; Kraus et al 2012). Only the first two have been found to display CO band emission, and detailed modeling will determine the kinematics of the CO gas and possibly help to distinguish between the scenarios of circumstellar or circumbinary origin (Muratore et al, in prep.…”

Section: Circumbinary Disk Of Gg Carmentioning

confidence: 99%

Molecular emission from GG Carinae’s circumbinary disk

Kraus

Oksala

Nickeler

et al. 2012

A&A

Self Cite

View full text Add to dashboard Cite

Context. The appearance of the B[e] phenomenon in evolved massive stars such as B [e] supergiants is still a mystery. While these stars are generally found to have disks that are cool and dense enough for efficient molecule and dust condensation, the origin of the disk material is still unclear. Aims. We aim at studying the kinematics and origin of the disk in the eccentric binary system GG Car, whose primary component is proposed to be a B[e] supergiant. Methods. Based on medium-and high-resolution near-infrared spectra we analyzed the CO-band emission detected from GG Car. The complete CO-band structure delivers information on the density and temperature of the emitting region, and the detectable 13 CO bands allow us to constrain the evolutionary phase. In addition, the kinematics of the CO gas can be extracted from the shape of the first 12 CO band head. Results. We find that the CO gas is located in a ring surrounding the eccentric binary system, and its kinematics agrees with Keplerian rotation with a velocity, projected to the line of sight, of 80 ± 1 km s −1 . The CO ring has a column density of (5 ± 3) × 10 21 cm −2 and a temperature of 3200 ± 500 K. In addition, the material is chemically enriched in 13 C, which agrees with the primary component being slightly evolved off the main sequence. We discuss two possible scenarios for the origin of the circumbinary disk: (i) nonconservative Roche lobe overflow; and (ii) the possibility that the progenitor of the primary component could have been a classical Be star. Neither can be firmly excluded, but for Roche lobe overflow to occur, a combination of stellar and orbital parameter extrema would be required.

show abstract

Section: Circumbinary Disk Of Gg Carmentioning

confidence: 99%

Molecular emission from GG Carinae’s circumbinary disk

Kraus

Oksala

Nickeler

et al. 2012

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…To match the data with the model, we interpolated the parameters for other wavelengths using cubic spline interpolation. The global optimum of the fit was found using a set of simulated annealing algorithms complemented by standard gradient descent algorithms (see Millour et al 2009, for a first application of this approach). A model with three spots (i.e., performing a fit with a uniform disk, a Gaussian disk, and three spots) significantly enhance the fit (χ 2 ≈ 25), especially for the visibilities and closure phases up to spatial frequency of ≈240 cycles/arcsec.…”

Section: Geometrical Toy Modelsmentioning

confidence: 99%

VLTI/AMBER spectro-interferometric imaging of VX Sagittarii's inhomogenous outer atmosphere

Chiavassa¹,

Lacour²,

Millour³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

Aims. We aim to explore the photosphere of the very cool late-type star VX Sgr and in particular the characterization of molecular layers above the continuum forming photosphere. Methods. We obtained interferometric observations with the VLTI/AMBER interferometer using the fringe tracker FINITO in the spectral domain 1.45−2.50 μm with a spectral resolution of ≈35 and baselines ranging from 15 to 88 m. We performed independent image reconstruction for different wavelength bins and fit the interferometric data with a geometrical toy model. We also compared the data to 1D dynamical models of Miras atmosphere and to 3D hydrodynamical simulations of red supergiant (RSG) and asymptotic giant branch (AGB) stars. Results. Reconstructed images and visibilities show a strong wavelength dependence. The H-band images display two bright spots whose positions are confirmed by the geometrical toy model. The inhomogeneities are qualitatively predicted by 3D simulations. At ≈2.00 μm and in the region 2.35−2.50 μm, the photosphere appears extended and the radius is larger than in the H band. In this spectral region, the geometrical toy model locates a third bright spot outside the photosphere that can be a feature of the molecular layers. The wavelength dependence of the visibility can be qualitatively explained by 1D dynamical models of Mira atmospheres. The best-fitting photospheric models show a good match with the observed visibilities and give a photospheric diameter of Θ = 8.82 ± 0.50 mas. The H 2 O molecule seems to be the dominant absorber in the molecular layers. Conclusions. We show that the atmosphere of VX Sgr seems to resemble Mira/AGB star model atmospheres more closely than do RSG model atmospheres. In particular, we see molecular (water) layers that are typical of Mira stars.

show abstract

“…Oudmaijer et al (1998) argue that HD 87643 is an evolved B[e] star (see also Kraus 2009). Millour et al (2009) based on AMBER-VLTI observations reported a close companion at 34 mas.…”

Section: Introductionmentioning

confidence: 99%

A survey for near-infrared H₂emission in Herbig Ae/Be stars: emission from the outer disks of HD 97048 and HD 100546

Plas

Ancker

Audard

et al. 2011

A&A

Self Cite

View full text Add to dashboard Cite

We report on a sensitive search for H 2 1-0 S(1), 1-0 S(0) and 2-1 S(1) ro-vibrational emission at 2.12, 2.22 and 2.25 μm in a sample of 15 Herbig Ae/Be stars employing CRIRES, the ESO-VLT near-infrared high-resolution spectrograph, at R ∼ 90 000. We report the detection of the H 2 1-0 S(1) line toward HD 100546 and HD 97048. In the other 13 targets, the line is not detected. The H 2 1-0 S(0) and 2-1 S(1) lines are undetected in all sources. These observations are the first detection of near-IR H 2 emission in HD 100546. The H 2 1-0 S(1) lines observed in HD 100546 and HD 97048 are observed at a velocity consistent with the rest velocity of both stars, suggesting that they are produced in the circumstellar disk. In HD 97048 the emission is spatially resolved and it is observed to extend at least up to 200 AU from the star. We report an increase of one order of magnitude in the H 2 1-0 S(1) line flux with respect to previous measurements taken in 2003 for this star, which suggests line variability. In HD 100546 the emission is tentatively spatially resolved and may extend at least up to 50 AU from the star. Modeling of the H 2 1-0 S(1) line profiles and their spatial extent with flat Keplerian disks shows that most of the emission is produced at a radius larger than 5 AU. Upper limits to the H 2 1-0 S(0)/1-0 S(1) and H 2 2-1 S(1)/1-0 S(1) line ratios in HD 97048 are consistent with H 2 gas at T > 2000 K and suggest that the emission observed may be produced by X-ray excitation. The upper limits for the line ratios for HD 100546 are inconclusive. Because the H 2 emission is located at large radii, for both sources a thermal emission scenario (i.e., gas heated by collisions with dust) is implausible. We argue that the observation of H 2 emission at large radii may be indicative of an extended disk atmosphere at radii >5 AU. This may be explained by a hydrostatic disk in which gas and dust are thermally decoupled or by a disk wind caused by photoevaporation.

show abstract

A binary engine fuelling HD 87643's complex circumstellar environment

Cited by 58 publications

References 38 publications

Molecular emission from GG Carinae’s circumbinary disk

Molecular emission from GG Carinae’s circumbinary disk

VLTI/AMBER spectro-interferometric imaging of VX Sagittarii's inhomogenous outer atmosphere

A survey for near-infrared H₂emission in Herbig Ae/Be stars: emission from the outer disks of HD 97048 and HD 100546

Contact Info

Product

Resources

About

A binary engine fuelling HD 87643's complex circumstellar environment

Cited by 58 publications

References 38 publications

Molecular emission from GG Carinae’s circumbinary disk

Molecular emission from GG Carinae’s circumbinary disk

VLTI/AMBER spectro-interferometric imaging of VX Sagittarii's inhomogenous outer atmosphere

A survey for near-infrared H2emission in Herbig Ae/Be stars: emission from the outer disks of HD 97048 and HD 100546

Contact Info

Product

Resources

About

A survey for near-infrared H₂emission in Herbig Ae/Be stars: emission from the outer disks of HD 97048 and HD 100546