Related papers: Australia Telescope Compact Array imaging of circu…

Using a combination of data from the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), the Arizona Radio Observatory Kitt Peak 12m telescope and the Arizona Radio Observatory 10m Heinrich Hertz Telescope, we have studied…

H13CN J=8-7 sub-millimetre line emission produced in the circumstellar envelope around the extreme carbon star IRC+10216 has been imaged at sub-arcsecond angular resolution using the SMA. Supplemented by a detailed excitation analysis the…

Aims: The detached shells carry information on their formation process, as well as on the small-scale structure of the circumstellar medium around AGB stars due to the absence of significant line-of-sight confusion. Methods: The youngest…

Context. HCN is a major constituent of the circumstellar envelopes of carbon-rich evolved stars, and rotational lines from within its vibrationally excited states probe parts of these regions closest to the stellar surface. A number of such…

Stars on the asymptotic giant branch (AGB) lose substantial amounts of matter, to the extent that they are important for the chemical evolution of, and dust production in, the universe. The mass loss is believed to increase gradually with…

This paper presents interferometric and single-dish CO observations along with HI data obtained for the oxygen-rich semi-regular variable RS Cnc, in order to probe its circumstellar environment at different scales. With the Plateau de Bure…

We used the ARO 12m antenna to observe emission from the J=1-0 lines of carbon monoxide, \hcop\ and HNC and the J=2-1 line of CS toward and around the continuum peak used for absorption studies and we compare them with CH, HNC, C\p\ and…

Y CVn is a carbon star surrounded by a detached dust shell that has been imaged by the Infrared Space Observatory at 90 microns. With the Nancay Radio Telescope we have studied the gaseous counterpart in the 21-cm HI emission line. New data…

In this Letter we report the CO abundance relative to H2 derived toward the circumstellar disk of the T-Tauri star TW Hya from the HD (1-0) and C18O (2-1) emission lines. The HD (1-0) line was observed by the Herschel Space Observatory…

Context. Radio frequency molecular absorption lines appear along sight lines with AV well below 1 mag, revealing the presence of H2 in diffuse gas even when 2.6mm CO emission is absent. Aims. We discuss absorption lines of HCO+, C2H, HCN,…

We present a millimetre molecular line survey of seven high mass loss rate carbon stars in both the northern and southern skies. A total of 196 emission lines (47 transitions) from 24 molecular species were detected. The observed CO…

We present new results of a spectroscopic survey of circumstellar HI in the direction of evolved stars made with the Nancay Radiotelescope. The HI line at 21 cm has been detected in the circumstellar shells of a variety of evolved stars:…

We report on the detection of HCO+ and 12CO emission in the rotational transition J=1-0 in the vicinity of the shock front at the southern border of the supernova remnant RCW 103, where previous infrared observations suggest an interaction…

Abridged. The 12CO/13CO ratio in the circumstellar envelope (CSE) of asymptotic giant branch (AGB) stars has been extensively used as the tracer of the photospheric 12C/13C ratio. However, spatially-resolved ALMA observations of R Scl, a…

We present Submillimeter Array observations toward the 10^{4.7} Lsun star-forming region G240.31+0.07, in the J=2-1 transition of 12CO and 13CO and at 1.3 mm continuum, as well as the 12CO and 13CO observations from the Caltech…

A multi-transition survey of HCN (sub-) millimeter line emission from a large sample of AGB stars of different chemical type is presented. The data are analysed and circumstellar HCN abundances are estimated. The sample stars span a large…

We present results from a search for 21 cm associated HI absorption in a sample of 29 radio sources selected from the Australia Telescope 20 GHz survey. Observations were conducted using the Australia Telescope Compact Array Broadband…

We present a CO(1-0) survey for cold molecular gas in a representative sample of 13 high-z radio galaxies (HzRGs) at 1.4<z<2.8, using the Australia Telescope Compact Array. We detect CO(1-0) emission associated with five sources: MRC…

We report the results of a high spatial (parsec) resolution HCO+ (J = 1-0) and HCN (J = 1-0) emission survey toward the giant molecular clouds of the star formation regions N105, N113, N159, and N44 in the Large Magellanic Cloud. The HCO+…

We have obtained maps of the molecular emission within the central five arcminutes (12 pc) of the Galactic center (GC) in selected molecular tracers: SiO(2-1), HNCO(5_{0,5}-4_{0,4}), and the J=1-->0 transition of H^{13}CO+, HN^{13}C, and…