Related papers: Systematic Theoretical Study on the Interstellar C…
Molecular hydrogen being unobservable in cold molecular clouds, the column density measurements of molecular gas currently rely either on dust emission observation in the far-IR or on star counting. (Sub-)millimeter observations of numerous…
Cyanoformaldehyde (HCOCN) molecule has recently been suspected towards the Sagittarius B2(N) by the Green Bank telescope, though a confirmation of this observation has not yet been made. In and around a star forming region, this molecule…
The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…
Starless molecular cores are natural laboratories for interstellar molecular chemistry research. The chemistry of ices in such objects was investigated with a three-phase (gas, surface, and mantle) model. We considered the center part of…
This paper is the fourth and final report on a project designed to study carbon abundances in a sample of planetary nebulae representing a broad range in progenitor mass and metallicity. We present newly acquired optical spectrophotometric…
We have imaged emission from the millimeter lines of eight molecules--C2H, C34S, N2H+, CH3OH, HNCO, HNC, HC3N, and SO--in the central half kpc of the nearby spiral galaxy IC 342. The 5" (~50 pc) resolution images were made with OVRO. Using…
The nearby Sy 1 galaxy NGC 1097 represents an ideal laboratory to explore the molecular chemistry in the presence and surroundings of an active galactic nucleus. Exploring the distribution of different molecular species allows us to…
Interstellar hydrides -- that is, molecules containing a single heavy element atom with one or more hydrogen atoms -- were among the first molecules detected outside the solar system. They lie at the root of interstellar chemistry, being…
Estimating molecular abundances ratios from the direct measurement of the emission of the molecules towards a variety of interstellar environments is indeed very useful to advance in our understanding of the chemical evolution of the…
A major limitation and a continuing source of confusion in the interpretation of molecular line observations has been the large degree of chemical complexity that is observed in star-forming molecular cores. The past decade has seen…
Almost 20% of the ~ 200 different species detected in the interstellar and circumstellar media present a carbon atom linked to nitrogen by a triple bond. Among these 37 molecules, 30 are nitrile R-CN compounds, the remaining seven belonging…
The aim of this work is to shed some light on the problem of the formation of carbon stars of R-type from a detailed study of their chemical composition. We use high-resolution and high signal-to-noise optical spectra of 23 R-type stars…
We present an unbiased molecular line survey toward the carbon-rich circumstellar envelope CIT 6 carried out between 90 and 116 GHz with the Arizona Radio Observatory 12 m telescope. A total of 42 lines assigned to 10 molecular species and…
The detection of a branched alkyl molecule in the high-mass star forming protocluster Sgr B2(N) permitted by the advent of ALMA revealed a new dimension of interstellar chemistry. Astrochemical simulations subsequently predicted that beyond…
Since molecules are ubiquitous in space, the study of the 'Molecular Universe' could unfold the mystery of the existing Interstellar medium. Star formation is linked to the chemical evolution processes. Thus, an analysis of the formation of…
The cumulene carbenes are important components of hydrocarbon chemistry in low mass star forming cores. Here we report the first astronomical detection of the long chain cumulene carbene H_2C_6 in the interstellar cloud TMC1, from…
We have observed the HC3N (J=10-9) and N2H+ (J=1-0) lines toward the Vela C molecular clouds with the Mopra 22 m telescope to study chemical characteristics of dense cores. The intensity distributions of these molecules are similar to each…
The cyano radical (CN), one of the first detected interstellar molecular species, is a key molecule in many astrochemical chains. Particularly, it is detected towards molecular cores, the birth places of the stars, and it is known that it…
This paper presents the first substantial study of the chemistry of the envelopes around a sample of 18 low-mass pre- and protostellar objects for which physical properties have previously been derived from radiative transfer modeling of…
It is long debated if pre-biotic molecules are indeed present in the interstellar medium. Despite substantial works pointing to their existence, pre-biotic molecules are yet to be discovered with a complete confidence. In this paper, our…