We present column density measurements of the HD molecule in the interstellar gas toward 17 Galactic stars. The values for the seven most heavily reddened sightlines, with E(B − V) = 0.38–0.72, are derived from observations with the Far Ultraviolet Spectroscopic Explorer (FUSE). The other ten values are from a reanalysis of spectra obtained with Copernicus. In all cases, high-resolution ground-...

A solid-state feature was detected at around 2175 cm−1 towards 30 embedded young stellar objects in spectra obtained using the Infrared Spectrometer and Array Camera at the European Southern Observatory Very Large Telescope. We present results from laboratory studies of CO adsorbed at the surface of zeolite wafers, where absorption bands were detected at 2177 and 2168 cm−1 (corresponding to CO ...

Intriguing propynal (HCCCHO) has been attracting chemist’s attention since 1955. However, to date, no satisfying conclusion concerning its formation mechanism in the interstellar medium (ISM) has been reached, although a variety of gas-reaction models, including ion-molecule, radical-molecule, and molecule-molecule, have been postulated. In this paper, we consider for the first time the gas-gra...

The three-carbon keto ring cyclopropenone (c-H2C 3O) has been detected largely in absorption with the 100 m Green Bank Telescope (GBT) toward the star-forming region Sagittarius B2(N) by means of a number of rotational transitions between energy levels that have energies less than 10 K. Previous negative results from searches for interstellar c-H2C3O by other investigators attempting to detect ...

A previous report that the interstellar molecule glycolaldehyde (HOCH(2)CHO) can be made from hydroxymethylene (HOCH:) and formaldehyde has been revisited at the CCSD(T)/6-311++G(3df,2p)//MP2/6-311++G(3df,2p) level of theory. This reaction competes with the formation of acetic acid and methylformate, molecules which have also been detected in interstellar clouds. Other possible modes of formati...

Organic molecules in interstellar space likely play a role in prebiotic chemistry. Hence, it is very important to properly identify the organic species present and to accurately evaluate their abundance. Owing to the rich molecular spectra found in many interstellar sources, accurate laboratory rest frequency measurements are crucial to accomplish these goals. Two key molecules are hydroxyaceto...

We describe the isolation and spectroscopic characterization of the heavier phosphorus-containing analogue of isocyanic acid (HPCO), and its isotopologue (DPCO). This fundamental small molecule, which has been postulated to exist in interstellar space, has thus far only been observed at low gas phase concentrations or in inert gas matrices. In this report we describe its synthesis, spectroscopi...

We present a theoretical investigation of the chemistry of fluorine-bearing molecules in diffuse and dense interstellar gas clouds, combining recent estimates for the rates of relevant chemical reactions with a self-consistent model for the physical and chemical conditions within gas clouds that are exposed to the interstellar ultraviolet radiation field. The chemistry of interstellar fluorine ...

This paper presents a possible way to understand dissolution of OB associations (or groups). Assuming rapid escape of parental cloud gas from associations, we show that the shadow of the formation environment for associations can be partially imprinted on the velocity dispersion at their dissolution. This conclusion is not surprising as long as associations are formed in a multiphase interstell...