Related papers: ALMA view of the circumstellar environment of the …

Context. Many protoplanetary nebulae show strong asymmetries in their surrounding shell, pointing to asymmetries during the mass loss phase. Questions concerning the origin and the onset of deviations from spherical symmetry are important…

We present 3D hydrodynamic models of the interaction between the outflows of evolved, pulsating, Asymptotic Giant Branch (AGB) stars and nearby ($< 3$ stellar radii) sub-stellar companions ($M_{\mathrm{comp}} \lesssim 40$ M$_J$). Our models…

Studying the appearance and properties of bipolar winds is critical to understand the stellar evolution from the AGB to the planetary nebula (PN) phase. Many uncertainties exist regarding the presence and role of binary stellar systems,…

We present results of an analysis of the optical spectrum of the post-AGB star HD56126 (IRAS 07134+1005) based on observations made with the echelle spectrographs of the 6-m telescope with spectral resolutions of R=25000 and 60000 at…

Recent observations of strikingly well-defined spirals in the circumstellar envelopes of asymptotic giant branch (AGB) stars point to the existence of binary companions in these objects. In the case of planet or brown dwarf mass companions,…

We present an analysis of the molecular and atomic gas emission in the rest-frame far-infrared and sub-millimetre, from the lensed z=2.3 sub-millimetre galaxy SMM J2135-0102. We obtain very high signal-to-noise detections of 11 transitions…

Despite being $>10$Myr, there are $\sim$10 debris discs with as much CO gas as in protoplanetary discs. Such discs have been assumed to be "hybrid", i.e., with secondary dust but primordial gas. Here we show that both the dust and gas in…

Circumstellar disks around stars older than 10 Myr are expected to be gas-poor. There are, however, two examples of old (30-40 Myr) debris-like disks containing a detectable amount of cold CO gas. Here we present ALMA and Herschel Space…

We have observed the Class I protostar TMC-1A with Atacama Millimeter/submillimeter Array (ALMA) in 12CO and C18O (J=2-1), and 1.3-mm dust continuum emission. Continuum emission with a deconvolved size of 0.50"x0.37", perpendicular to the…

Born-again stars allow probing stellar evolution in human timescales and provide the most promising path for the formation of hydrogen-deficient post-asymptotic giant branch objects, but their cold and molecular components remain poorly…

During their thermally pulsing phase, Asymptotic Giant Branch (AGB) stars eject material that forms extended dusty envelopes. Visible polarimetric imaging found clumpy dust clouds within two stellar radii of several oxygen-rich stars.…

We present our recent results on mm-wave CO observations of proto-planetary nebulae. These include high-resolution interferometric maps of various CO lines in three well known bipolar PPNe: M1-92, M2-56 and OH231.8+4.2. The global…

There is a class of binary post-asymptotic giant branch (post-AGB) stars that exhibit remarkable near-infrared (NIR) excess. These stars are surrounded by disks with Keplerian or quasi-Keplerian dynamics and outflows composed of gas…

We report the small-scale spatial variation in cool ($T\sim 10^4 K$) Mg II absorption detected in the circumgalactic medium (CGM) of a star-forming galaxy at $z\approx 0.8$. The CGM of this galaxy is probed by a spatially extended bright…

Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary…

Post-asymptotic giant branch (post-AGB) binaries are surrounded by dusty circumbinary disks, and exhibit unexpected orbital properties resulting from poorly understood binary interaction processes. Re-accreted gas from the circumbinary disk…

We present ALMA continuum observations at a wavelength of 1.25 mm of the debris disk surrounding the $\sim$ 100 Myr old solar analog HD 107146. The continuum emission extends from about 30 to 150 AU from the central star with a decrease in…

We study the morpho-kinematics of the circumbinary envelope of Mira Ceti between $\sim$100 and $\sim$350 au from the stars using ALMA observations of the SiO ($\nu$=0, $J$=5-4) and CO ($\nu$=0, $J$=3-2) emissions with the aim of presenting…

We present a sub-100 pc-scale analysis of the CO molecular gas emission and kinematics of the gravitational lens system SDP.81 at redshift 3.042 using Atacama Large Millimetre/submillimetre Array (ALMA) science verification data and a…

We present a new study of archival ALMA observations of the CO(2-1) line emission of the host galaxy of quasar RX J1131 at redshift $z$=0.654, lensed by a foreground galaxy. A simple lens model is shown to well reproduce the optical images…