Morpho-kinematics of the circumstellar envelope of the AGB star R Dor: a global view

Abstract

We analyse new ALMA observations of the ${}^{29}$SiO ($\nu$=0, $J$=8$-$7) and SO${}_2$($\nu$=0, $34_{3,31}$$-$$34_{2,32}$) line emissions of the circumstellar envelope (CSE) of the oxygen-rich AGB star R Dor. With a spatial resolution of $\sim$2.3 au, they cover distances below $\sim$30 au from the star providing a link between earlier observations and clarifying some open issues. The main conclusions are: 1) Rotation is confined below $\sim$15 au from the star, with velocity reaching a maximum below 10 au and morphology showing no significant disc-like flattening. 2) In the south-eastern quadrant, a large Doppler velocity gas stream is studied in more detail than previously possible and its possible association with an evaporating planetary companion is questioned. 3) A crude evaluation of the respective contributions of rotation, expansion and turbulence to the morpho-kinematics is presented. Significant line broadening occurs below $\sim$12 au from the star and causes the presence of high Doppler velocity components near the line of sight pointing to the centre of the star. 4) Strong absorption of the continuum emission of the stellar disc and its immediate dusty environment is observed to extend beyond the disc in the form of self-absorption. The presence of a cold SiO layer extending up to some 60 au from the star is shown to be the cause. 5) Line emissions from SO, ${}^{28}$SiO, CO and HCN molecules are used to probe the CSE up to some 100 au from the star and reveal the presence of two broad back-to-back outflows, the morphology of which is studied in finer detail than in earlier work.

arXiv comment20 pages, 26 figures, accepted for publication in MNRAS

References in corpus (27)

• Hot Jupiters and Cool Stars
• Too little radiation pressure on dust in the winds of oxygen-rich AGB stars
• A close halo of large transparent grains around extreme red giant stars
• Reprocessing the Hipparcos data for evolved stars III Revised Hipparcos period-luminosity relationship for galactic long-period variable stars
• Global 3D radiation-hydrodynamics models of AGB stars. Effects of convection and radial pulsations on atmospheric structures
• The abundance of HCN in circumstellar envelopes of AGB stars of different chemical types
• Line formation in AGB atmospheres including velocity effects. Molecular line profile variations of long period variables
• Study of the inner dust envelope and stellar photosphere of the AGB star R Doradus using SPHERE/ZIMPOL
• Tracing the phase transition of Al-bearing species from molecules to dust in AGB winds. Constraining the presence of gas-phase (Al2O3)n clusters
• New insights into the dust formation of oxygen-rich AGB stars
• Mode switching in the nearby Mira-like variable R Doradus
• ALMA spectral line and imaging survey of a low and a high mass-loss rate AGB star between 335 and 362 GHz
• Sulphur molecules in the circumstellar envelopes of M-type AGB stars
• The 12CO/13CO ratio in AGB stars of different chemical type-Connection to the 12C/13C ratio and the evolution along the AGB
• A HIFI view on circumstellar H2O in M-type AGB stars: radiative transfer, velocity profiles, and H2O line cooling
• Resolving the extended atmosphere and the inner wind of Mira ($o$ Ceti) with long ALMA baselines
• Probing the inner wind of AGB stars: Interferometric observations of SiO millimetre line emission from the oxygen-rich stars R Dor and L2 Pup
• Chemical content of the circumstellar envelope of the oxygen-rich AGB star R Dor: Non-LTE abundance analysis of CO, SiO, and HCN
• Resolving the extended stellar atmospheres of Asymptotic Giant Branch stars at (sub-)millimetre wavelengths
• Rotation of the asymptotic giant branch star R Doradus
• Circumstellar environment of the M-type AGB star R Dor. APEX spectral scan at $159.0-368.5$ GHz
• ALMA detection of a tentative nearly edge-on rotating disk around the nearby AGB star R~Doradus
• An ALMA view of CS and SiS around oxygen-rich AGB stars
• Water isotopologues in the circumstellar envelopes of M-type AGB stars
• An ALMA view of SO and SO${}_2$ around oxygen-rich AGB stars
• Detection of highly excited OH towards AGB stars: A new probe of shocked gas in the extended atmospheres
• The nascent wind of AGB star R Doradus: evidence for a recent episode of enhanced mass loss

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