Related papers: The chemistry of interstellar molecules containing…
We present a theoretical investigation of the chemistry of fluorine-bearing molecules in diffuse and dense interstellar gas clouds. The chemistry of interstellar fluorine is qualitatively different from that of any other element, because -…
We have revisited the chemistry of chlorine-bearing species in the diffuse interstellar medium with new observations of the HCl$^+$ molecular ion and new astrochemical models. Using the GREAT instrument on board SOFIA, we observed the…
We report the first detection of chloronium, H$_2$Cl$^+$, in the interstellar medium, using the HIFI instrument aboard the \emph{Herschel} Space Observatory. The $2_{12}-1_{01}$ lines of ortho-H$_2^{35}$Cl$^+$ and ortho-H$_2^{37}$Cl$^+$ are…
Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared (HIFI), we have observed para-chloronium (H2Cl+) toward six sources in the Galaxy. We detected interstellar chloronium absorption in foreground molecular…
We report the detection of hydrogen chloride, HCl, in diffuse molecular clouds on the line of sight towards the star-forming region W31C (G10.6-0.4). The J = 1-0 lines of the two stable HCl isotopologues, H35Cl and H37Cl, are observed using…
The transition between atomic and molecular hydrogen is associated with important changes in the structure of interstellar clouds, and marks the beginning of interstellar chemistry. Because of the relatively simple networks controlling…
We discuss the first astronomical detection of the CF+ (fluoromethylidynium) ion, obtained by observations of the J=1-0 (102.6 GHz), J=2-1 (205.2 GHz) and J=3-2 (307.7 GHz) rotational transitions toward the Orion Bar region. Our search for…
We present a comprehensive examination of interstellar P and Cl abundances based on an analysis of archival spectra acquired with the Space Telescope Imaging Spectrograph of the Hubble Space Telescope and the Far Ultraviolet Spectroscopic…
The freezeout of gas-phase species onto cold dust grains can drastically alter the chemistry and the heating-cooling balance of protostellar material. In contrast to well-known species such as carbon monoxide (CO), the freezeout of various…
In diffuse interstellar clouds the chemistry that leads to the formation of the oxygen bearing ions OH+, H2O+, and H3O+ begins with the ionization of atomic hydrogen by cosmic rays, and continues through subsequent hydrogen abstraction…
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.…
Context. The chemistry of the diffuse interstellar medium rests upon three pillars: exothermic ion-neutral reactions (" cold chemistry "), endothermic neutral-neutral reactions with significant activation barriers (" warm chemistry "), and…
HCl and HF are expected to be the main reservoirs of fluorine and chlorine wherever hydrogen is predominantly molecular. They are found to be strongly depleted in dense molecular clouds, suggesting freeze-out onto grains in such cold…
Chlorine (Cl) is a chemical element of the group of the halogens and is between the 17th and the 20th most abundant elements in the Solar System. It is thought to be produced from the capture of a proton or neutron by specific alpha-element…
Hydrogen fluoride has been established to be an excellent tracer of molecular hydrogen in diffuse clouds. In denser environments, however, the HF abundance has been shown to be approximately two orders of magnitude lower. We present…
We combine Herschel observations of a total of 12 sources to construct the most uniform survey of HF and H2O in our Galactic disk. Both molecules are detected in absorption along all sight lines. The high spectral resolution of the…
We discuss the detection of absorption by interstellar hydrogen fluoride (HF) along the sight line to the submillimeter continuum sources W49N and W51. We have used Herschel's HIFI instrument in dual beam switch mode to observe the…
We present a general parameter study, in which the abundance of interstellar argonium (ArH$^+$) is predicted using a model for the physics and chemistry of diffuse interstellar gas clouds. Results have been obtained as a function of UV…
High quality archival spectra of interstellar absorption from C I toward 9 stars, taken with the Goddard High Resolution Spectrograph on the Hubble Space Telescope, were analyzed. Our sample was supplemented by two sight lines, 23 Ori and…
We carried out an observational search for the recently discovered molecule H2NC, and its more stable isomer H2CN, toward eight cold dense clouds (L1544, L134N, TMC-2, Lupus-1A, L1489, TMC-1 NH3, L1498, and L1641N) and two diffuse clouds…