Related papers: Detection of Formaldehyde Towards the Extreme Carb…

In this paper we study the oxygen chemistry in the C-rich circumstellar shells of IRC+10216. The recent discoveries of oxygen bearing species (water, hydroxyl radical and formaldehyde) toward this source challenge our current understanding…

The circumstellar envelopes of carbon-rich AGB stars show a chemical complexity that is exemplified by the prototypical object IRC +10216, in which about 60 different molecules have been detected to date. Most of these species are carbon…

We report the detection of emission in the J=1-0 rotational transition of hydrogen fluoride (HF), together with observations of the J=1-0 to J=3-2 rotational lines of H35Cl and H37Cl, towards the envelope of the carbon star IRC +10216.…

A new chemical model is presented for the carbon-rich circumstellar envelope of the AGB star IRC+10216. The model includes shells of matter with densities that are enhanced relative to the surrounding circumstellar medium. The chemical…

In recent years, many questions have arisen regarding the chemistry of photochemical products in the carbon-rich winds of evolved stars. To address them, it is imperative to constrain the distributions of such species through high angular…

AGB stars are major contributors to the chemical enrichment of the ISM through nucleosynthesis and extensive mass loss. Most of our current knowledge of AGB atmospheric and circumstellar chemistry, in particular in a C-rich environment, is…

We report on the detection of anhydrous hydrochloric acid (hydrogen chlorine, HCl) in the carbon-rich star IRC+10216 using the spectroscopic facilities onboard the Herschel satellite. Lines from J=1-0 up to J=7-6 have been detected. From…

Formaldehyde is a key precursor in the formation routes of many complex organic molecules (COMs) in space. It is also an intermediate step in CO hydrogenation sequence that leads to methanol formation on the surface of interstellar grains…

We present the detection of C4H2 for first time in the envelope of the C-rich AGB star IRC+10216 based on high spectral resolution mid-IR observations carried out with the Texas Echelon-cross-Echelle Spectrograph (TEXES) mounted on the…

Context: The presence of water in the wind of the extreme carbon star IRC+10216 has been confirmed by the Herschel telescope. The regions where the high-J H2O lines have been detected are close to the star at radii r \geq 15 R\ast. Aims: We…

We argue that the presence of water vapor in the circumstellar outflow of a carbon-rich AGB star is potentially a distinctive signature of extra-solar cometary systems. Detailed models show that at suitable distances from the star, water…

We report the detection of the 1665 and 1667 MHz main lines of OH (hydroxyl) and upper limits on the 1612 MHz satellite line of OH towards the carbon-rich AGB star, IRC+10216. We find a beam averaged fractional abundance x(OH)~4x10^{-8}.…

Asymptotic giant branch (AGB)stars create a rich inventory of molecules in their envelopes as they lose mass during later stages of their evolution. These molecules cannot survive the conditions in interstellar space, where they are exposed…

We present the results of our spectral line surveys in the 2 mm and 1.3 mm windows toward the carbon rich envelope of IRC +10216. Totally 377 lines are detected, among which 360 lines are assigned to 57 known molecules (including 29 rare…

We have used the Robert C. Byrd Green Bank Telescope to perform the most sensitive search to date for neutral atomic hydrogen (HI) in the circumstellar envelope (CSE) of the carbon star IRC+10216. Our observations have uncovered a low…

We report on the detection of vinyl cyanide (CH2CHCN), cyanomethyl radical (CH2CN), methylacetylene (CH3CCH) and thioformaldehyde (H2CS) in the C-rich star IRC +10216. These species, which are all known to exist in dark clouds, are detected…

IRC+10216 is the brightest infrared source in the northern sky, known for its rich chemical composition. It is often used as a standard reference for studying the circumstellar envelope (CSE) of carbon-rich stars. While pioneering 3\,mm…

Complex organic molecules (COMs) are detected in many regions of the interstellar medium, including prestellar cores. However, their formation mechanisms in cold (~10 K) cores remain to this date poorly understood. The formyl radical HCO is…

A CO(1-0) on-source spectrum of the well-known carbon star IRC+10216 taken with the IRAM 30m telescope in June 1996 shows excess emission between -18.3 and -14.3 km/s at the red wing of the underlying profile. The excess emission is…

Despite the organic molecule inventory detected in Orion KL, acetaldehyde (CH3CHO) -- one of the most ubiquitous interstellar aldehydes -- has not been firmly identified with mm-wave interferometry. We analyze extensive ALMA archival…