ALMA observations of CO(1-0) and CO(2-1) emissions of the circumstellar envelope of EP Aqr, an oxygen-rich AGB star, are reported. A thorough analysis of their properties is presented using an original method based on the separation of the data-cube into a low velocity component associated with an equatorial outflow and a faster component associated with a bipolar outflow. A number of important and new results are obtained concerning the distribution in space of the effective emissivity, the temperature, the density and the flux of matter. A mass loss rate of (1.6 ± 0.4)10 −7 solar masses per year is measured. The main parameters defining the morphology and kinematics of the envelope are evaluated and uncertainties inherent to de-projection are critically discussed. Detailed properties of the equatorial region of the envelope are presented including a measurement of the line width and a precise description of the observed inhomogeneity of both morphology and kinematics. In particular, in addition to the presence of a previously observed spiral enhancement of the morphology at very small Doppler velocities, a similarly significant but uncorrelated circular enhancement of the expansion velocity is revealed, both close to the limit of sensitivity. The results of the analysis place significant constraints on the parameters of models proposing descriptions of the mass loss mechanism, but cannot choose among them with confidence.

The CO(1−0) and (2−1) emission of the circumstellar envelope of the asymptotic giant branch (AGB) star EP Aqr has been observed in 2003 using the IRAM Plateau-de-Bure Interferometer and in 2004 with the IRAM 30-m telescope at Pico Veleta. The line profiles reveal the presence of two distinct components centred on the star velocity, a broad component extending up to ∼10 km s −1 and a narrow component indicating an expansion velocity of only ∼2 km s −1 . An early analysis of these data was performed under the assumption of isotropic winds. The present study revisits this interpretation, instead assuming a bipolar outflow nearly aligned with the line of sight. A satisfactory description of the observed flux densities is obtained with a radial expansion velocity increasing from ∼2 km s −1 at the equator to ∼10 km s −1 near the poles. The mass-loss rate is ∼1.2 × 10 −7 M yr −1 . The angular aperture of the bipolar outflow is ∼45• with respect to the star axis, which makes an angle of ∼13• with the line of sight. A detailed study of the CO(1−0) to CO(2−1) flux ratio reveals a significant dependence of the temperature on the stellar latitude, smaller and steeper at the poles than at the equator at large distances from the star (>2 ≡ 1.0 × 10 −3 pc). Under the hypothesis of radial expansion of the gas and of rotation invariance about the star axis, the effective density was evaluated in space as a function of star coordinates (longitude, latitude, and distance from the star). Evidence is found for an enhancement of the effective density in the northern hemisphere of the star at angular distances in excess of ∼3 and covering the whole longitudinal range. The peak velocity of the narrow component is observed to vary slightly with position on the sky, a variation consistent with the model and understood as the effect of the inclination of the star axis with respect to the line of sight. This variation is inconsistent with the assumption of a spherical wind and strengthens our interpretation in terms of an axisymmetric outflow. While the phenomenological model presented here reproduces well the general features of the observations, not only qualitatively but also quantitatively, significant differences are also revealed, which would require a better spatial resolution to be properly described and understood.

Using ALMA observations of 12 CO(2-1), 28 SiO(5-4) and 32 SO 2 (16 6,10 -17 5,13 ) emissions of the circumstellar envelope of AGB star EP Aqr, we describe the morpho-kinematics governing the nascent wind. Main results are: 1) Two narrow polar structures, referred to as jets, launched from less than 25 au away from the star, build up between ∼ 20 au and ∼ 100 au to a velocity of ∼ 20 km s −1 . They fade away at larger distances and are barely visible in CO data. 2) SO 2 , SiO and CO emissions explore radial ranges reaching respectively ∼30 au, 250 au and 1000 au from the star, preventing the jets to be detected in SO 2 data. 3) Close to the star photosphere, rotation (undetected in SiO and CO data) and isotropic radial expansion combine with probable turbulence to produce a broad SO 2 line profile (∼ 7.5 km s −1 FWHM). 4) A same axis serves as axis of rotation close to the star, as jet axis and as axi-symmetry axis at large distances. 5) A radial wind builds up at distances up to ∼ 300 au from the star, with larger velocity near polar than equatorial latitudes. 6) A sharp depletion of SiO and CO emissions, starting near the star, rapidly broadens to cover the whole blue-western quadrant, introducing important asymmetry in the CO and particularly SiO observations. 7) The 12 C/ 13 C abundance ratio is measured as 9±2. 8) Plausible interpretations are discussed, in particular assuming the presence of a companion.

Context. GG Tau A is the prototype of a young triple T Tauri star that is surrounded by a massive and extended Keplerian outer disk. The central cavity is not devoid of gas and dust and at least GG Tau Aa exhibits its own disk of gas and dust emitting at millimeter wavelengths. Its observed properties make this source an ideal laboratory for investigating planet formation in young multiple solartype stars. Aims. We used new ALMA 13 CO and C 18 O(3-2) observations obtained at high angular resolution (∼ 0.2 ) together with previous CO(3-2) and (6-5) ALMA data and continuum maps at 1.3 and 0.8 mm in order to determine the gas properties (temperature, density, and kinematics) in the cavity and to a lesser extent in the outer disk. Methods. By deprojecting, we studied the radial and azimuthal gas distribution and its kinematics. We also applied a new method to improve the deconvolution of the CO data and in particular better quantify the emission from gas inside the cavity. We perform local and nonlocal thermodynamic equilibrium studies in order to determine the excitation conditions and relevant physical parameters inside the ring and in the central cavity.Results. Residual emission after removing a smooth-disk model indicates unresolved structures at our angular resolution, probably in the form of irregular rings or spirals. The outer disk is cold, with a temperature < 20 K beyond 250 au that drops quickly (∝ r −1 ). The kinematics of the gas inside the cavity reveals infall motions at about 10% of the Keplerian speed. We derive the amount of gas in the cavity, and find that the brightest clumps, which contain about 10% of this mass, have kinetic temperatures 40 − 80 K, CO column densities of a few 10 17 cm −2 , and H 2 densities around 10 7 cm −3 . Conclusions. Although the gas in the cavity is only a small fraction of the disk mass, the mass accretion rate throughout the cavity is comparable to or higher than the stellar accretion rate. It is accordingly sufficient to sustain the circumstellar disks on a long timescale.

We analyse ALMA observations of the SO(J K = 6 5 − 5 4 ) emission of the circumstellar envelope of oxygen-rich AGB star R Dor, probing distances between 20 and 100 au from the star where the nascent wind is building up. We give evidence for the slow wind to host, in addition to a previously observed rotating disc, a radial outflow covering very large solid angles and displaying strong inhomogeneity both in direction and radially: the former takes the form of multiple cores and the latter displays a radial dependence suggesting an episode of enhanced mass loss having occurred a century or so ago.