The carbon star IRC+10216: linking the complex inner region with its spherical large-scale structures

Menut, Jean-Luc; Gendron, É.; Schartmann, M.; Tuthill, P. G.; López, B.; Danchi, W. C.; Wolf, S.; Lagrange, A.-M.; Flament, Stéphane; Rouan, D.; Clénet, Y.; Berruyer, N.

doi:10.1111/j.1745-3933.2006.00274.x

Cited by 16 publications

(18 citation statements)

References 22 publications

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“…We stress that the central region of the CSE of IRC +10216 has complex structures (see e.g., Tuthill et al 2005;Murakawa et al 2005;Leão et al 2006;Menut et al 2007;Fonfría et al 2014;Jeffers et al 2014;Decin et al 2015) and even binary system has been proposed (Decin et al 2015;Cernicharo et al 2015;Kim et al 2015). It is higher desirable to do high resolution observations to confirm the masers directly.…”

Section: Interpretation Of Line Shape Variationmentioning

confidence: 84%

Monitor Variability of Millimeter Lines in IRC+10216

Dinh-V-Trung

Hasegawa

2017

ApJ

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A single dish monitoring of millimeter maser lines SiS J=14-13 and HCN ν 2 = 1 f J=3-2 and several other rotational lines is reported for the archetypal carbon star IRC +10216. Relative line strength variations of 5%∼30% are found for eight molecular line features with respect to selected reference lines. Definite line-shape variation is found in limited velocity intervals of the SiS and HCN line profiles. The asymmetrical line profiles of the two lines are mainly due to the varying components. Their dominant varying components of the line profiles have similar periods and phases as the IR light variation, although both quantities show some degree of velocity dependence; there is also variability asymmetry between the blue and red line wings of both lines. Combining the velocities and amplitudes with a wind velocity model, we suggest that the line profile variations are due to SiS and HCN masing lines emanating from the wind acceleration zone. The possible link of the variabilities to thermal, dynamical and/or chemical processes within or under this region is also discussed.

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Section: Interpretation Of Line Shape Variationmentioning

confidence: 84%

Monitor Variability of Millimeter Lines in IRC+10216

Dinh-V-Trung

Hasegawa

2017

ApJ

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“…> ∼ 20% of the mass loss is concentrated in these clouds, with a filling factor <1%. Menut et al (2007) modelled IR interferometry of dust emission from within 300 AU of IRC+10216 using 500 clumps, ten-to a hundred-fold overdense, of the same radius as the star, which is similar to the wind structure deduced for our targets.…”

Section: Water Maser Clump Density and The Mass In Cloudsmentioning

confidence: 86%

Evolved star water maser cloud size determined by star size

Richards

Etoka

Gray

et al. 2012

A&A

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Context. Cool, evolved stars undergo copious mass loss but the detailed mechanisms and the form in which the matter is returned to the ISM are still under debate. Aims. We investigated the structure and evolution of the wind at 5 to 50 stellar radii from asymptotic giant branch and red supergiant stars. Methods. 22-GHz water masers around seven evolved stars were imaged using MERLIN, at sub-AU resolution. Each source was observed at between 2 and 7 epochs, covering several stellar periods. We compared our results with long-term single dish monitoring provided by the Pushchino radio telescope. Results. The 22-GHz emission is located in approximately spherical, thick, unevenly filled shells. The outflow velocity increases twofold or more between the inner and outer shell limits. Water maser clumps could be matched at successive epochs separated by less than two years for AGB stars, or at least 5 years for RSG. This is much shorter than the decades taken for the wind to cross the maser shell, and comparison with spectral monitoring shows that some features fade and reappear. In five sources, most of the matched maser features brighten or dim in concert from one epoch to the next. A number of individual maser features show idiosyncratic behaviour, including one cloud in W Hya caught in the act of passing in front of a background cloud leading to 50-fold, transient amplification. The masing clouds are one or two orders of magnitude denser than the wind average and contain a substantial fraction of the mass loss in this region, with a filling factor <1%. The RSG clouds are about ten times bigger than those round the AGB stars. Conclusions. Proper motions are dominated by expansion, with no systematic rotation. The maser clouds presumably survive for decades (the shell crossing time) but the masers are not always beamed in our direction. Only radiative effects can explain changes in flux density throughout the maser shells on short timescales. The size of the clouds is proportional to that of the parent star, being of a similar radius to the star once the clumps reach the 22-GHz maser shell. Stellar properties such as convection cells must determine the clumping scale.

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“…11. A possible mechanism for the formation of the dust is that it condenses in the shadow of source B, where the lower temperature would be more favorable to the survival of dust grains (Menut et al 2007). A relatively dense accretion disk around L 2 Pup B could also favor the formation of dust.…”

Section: Relation With the Nebular Featuresmentioning

confidence: 99%

ALMA observations of the nearby AGB star L₂ Puppis

Kervella

Homan

Richards

et al. 2016

A&A

133

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Six billion years from now, while evolving on the asymptotic giant branch (AGB), the Sun will metamorphose from a red giant into a beautiful planetary nebula. This spectacular evolution will impact the solar system planets, but observational confirmations of the predictions of evolution models are still elusive as no planet orbiting an AGB star has yet been discovered. The nearby AGB red giant L 2 Puppis (d = 64 pc) is surrounded by an almost edge-on circumstellar dust disk. We report new observations with ALMA at very high angular resolution (18 × 15 mas) in band 7 (ν ≈ 350 GHz) that allow us to resolve the velocity profile of the molecular disk. We establish that the gas velocity profile is Keplerian within the central cavity of the dust disk, allowing us to derive the mass of the central star L 2 Pup A, m A = 0.659 ± 0.011 ± 0.041 M (±6.6%). From evolutionary models, we determine that L 2 Pup A had a near-solar main-sequence mass, and is therefore a close analog of the future Sun in 5 to 6 Gyr. The continuum map reveals a secondary source (B) at a radius of 2 AU contributing f B / f A = 1.3 ± 0.1% of the flux of the AGB star. L 2 Pup B is also detected in CO emission lines at a radial velocity of v B = 12.2 ± 1.0 km s −1 . The close coincidence of the center of rotation of the gaseous disk with the position of the continuum emission from the AGB star allows us to constrain the mass of the companion to m B = 12 ± 16 M Jup . L 2 Pup B is most likely a planet or low-mass brown dwarf with an orbital period of about five years. Its continuum brightness and molecular emission suggest that it may be surrounded by an extended molecular atmosphere or an accretion disk. L 2 Pup therefore emerges as a promising vantage point on the distant future of our solar system.

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The carbon star IRC+10216: linking the complex inner region with its spherical large-scale structures

Cited by 16 publications

References 22 publications

Monitor Variability of Millimeter Lines in IRC+10216

Monitor Variability of Millimeter Lines in IRC+10216

Evolved star water maser cloud size determined by star size

ALMA observations of the nearby AGB star L₂ Puppis

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The carbon star IRC+10216: linking the complex inner region with its spherical large-scale structures

Cited by 16 publications

References 22 publications

Monitor Variability of Millimeter Lines in IRC+10216

Monitor Variability of Millimeter Lines in IRC+10216

Evolved star water maser cloud size determined by star size

ALMA observations of the nearby AGB star L2 Puppis

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Product

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ALMA observations of the nearby AGB star L₂ Puppis