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Related papers: ALMA Observations of W Hya: Impact of missing base…

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We report the first detection of a gap and a ring in 336 GHz dust continuum emission from the protoplanetary disk around TW Hya, using the Atacama Large Millimeter/Submillimeter Array (ALMA). The gap and ring are located at around 25 and 41…

Many aspects of the Atacama Large Millimeter Array (ALMA) instrument are still unknown due to its young age. One such aspect is the true nature of the primary beam of each baseline, and how changes to the individual primary beams affect…

Instrumentation and Methods for Astrophysics · Physics 2017-02-07 Kara Kundert , Urvashi Rau , Edwin Bergin , Sanjay Bhatnagar

ALMA's high-resolution images allow to resolve the filamentary structure of the ISM down to few thousand au at kpc distances. We aim to systematically quantify the impact of the interferometric response and the effects of the short-spacing…

Astrophysics of Galaxies · Physics 2024-08-07 F. Bonanomi , A. Hacar , A. Socci , D. Petry , S. Suri

We present high-angular-resolution imaging of the asymptotic giant branch star W Hya with the Atacama Large Millimeter/submillimeter Array (ALMA) to probe the dynamics and chemistry in the atmosphere and inner wind. W Hya was observed with…

Solar and Stellar Astrophysics · Physics 2025-12-04 K. Ohnaka , K. T. Wong , G. Weigelt , K. -H. Hofmann

The initial conditions for the mass loss during the asymptotic giant branch (AGB) phase are set in their extended atmospheres, where, among others, convection and pulsation driven shocks determine the physical conditions. High resolution…

Solar and Stellar Astrophysics · Physics 2019-06-19 W. H. T. Vlemmings , T. Khouri , H. Olofsson

Context. With the outstanding spatial resolution and sensitivity of the Atacama Large Millimeter/sub-millimeter Array (ALMA), molecular gas other than the abundant CO can be observed and resolved in circumstellar envelopes (CSEs) around…

In a radio interferometer, the determination of geometrical antenna positions relies on accurate calibration of the dry and wet delay of the atmosphere above each antenna. For the Atacama Large Millimeter/Submillimeter Array (ALMA), which…

Instrumentation and Methods for Astrophysics · Physics 2016-10-14 Todd R. Hunter , Robert Lucas , Dominique Broguiere , Ed B. Fomalont , William R. F. Dent , Neil Phillips , David Rabanus , Catherine Vlahakis

The unprecedented sensitivity of the Atacama Large millimeter/submillimeter array (ALMA) is providing many new discoveries. Several of these are serendipitous to the original goal of the observations. We report the discovery of previously…

Solar and Stellar Astrophysics · Physics 2016-01-21 W. Vlemmings , S. Ramstedt , M. Maercker , B. Davidsson

We present Atacama Large Millimeter Array (ALMA) observations of TW Hya at 0.65 mm with 0.5 arcsecond angular resolution, together with high angular resolution archival observations at 0.87 mm, 1.3 mm, 2.1 mm and 3.1 mm. We constrain the…

Earth and Planetary Astrophysics · Physics 2024-09-11 Sreejita Das , Nicolas T. Kurtovic , Mario Flock

Our recent visible polarimetric images of the well-studied AGB star W Hya taken at pre-maximum light (phase 0.92) with VLT/SPHERE-ZIMPOL have revealed clumpy dust clouds close to the star at ~2 Rstar. We present second-epoch SPHERE-ZIMPOL…

Solar and Stellar Astrophysics · Physics 2016-12-21 Keiichi Ohnaka , Gerd Weigelt , Karl-Heinz Hofmann

We present long-baseline Atacama Large Millimeter/submillimeter Array (ALMA) observations of the 870 micron continuum emission from the nearest gas-rich protoplanetary disk, around TW Hya, that trace millimeter-sized particles down to…

We aim to constrain the sizes of the CO circumstellar envelopes (CSEs) of 16 S-type stars, along with an additional 7 and 4 CSEs of C-type and M-type AGB stars, respectively. We map the emission from the CO J=2-1 and 3-2 lines observed with…

Low- and intermediate-mass stars evolve through the asymptotic giant branch (AGB), when an efficient mass-loss process removes a significant fraction of their initial mass. A substantial increase in the mass-loss rate at the end of the AGB…

We present visible polarimetric imaging observations of the well-studied AGB star W Hya taken with VLT/SPHERE-ZIMPOL as well as high spectral resolution long-baseline interferometric observations with the AMBER instrument of the Very Large…

Solar and Stellar Astrophysics · Physics 2016-04-20 Keiichi Ohnaka , Gerd Weigelt , Karl-Heinz Hofmann

We present new Atacama Large Millimeter/Submillimeter Array (ALMA) 850um continuum observations of the original Lyman-alpha Blob (LAB) in the SSA22 field at z=3.1 (SSA22-LAB01). The ALMA map resolves the previously identified submillimeter…

We present observations of a giant Lyman-alpha blob in the SSA22 proto-cluster at z=3.1, SSA22-LAB1, taken with the Atacama Large Millimeter/submillimeter Array (ALMA). Dust continuum, along with [C II]158um, and CO(4-3) line emission have…

Observation of CO emission around asymptotic giant branch (AGB) stars is the primary method to determine gas mass-loss rates. While radiative transfer models have shown that molecular levels of CO can become mildly inverted, causing maser…

Solar and Stellar Astrophysics · Physics 2021-10-04 W. H. T. Vlemmings , T. Khouri , D. Tafoya

Galaxy morphology is shaped by stellar activity, feedback, gas and dust properties, and interactions with surroundings, and can therefore provide insight into these processes. In this paper, we study the spatial offsets between stellar and…

The CO(J=3-2) emission from the CSE of the binary S-type AGB star W Aql has been observed at subarcsecond resolution using ALMA. The aim of this paper is to investigate the wind properties of the AGB star and to analyse how the known…

Asymptotic giant branch (AGB) stars lose their envelopes by means of a stellar wind whose driving mechanism is not understood well. Characterizing the composition and thermal and dynamical structure of the outflow provides constraints that…

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