Radio Observations of OH in the Interstellar Medium

  title={Radio Observations of OH in the Interstellar Medium},
  author={Sander Weinreb and Alan H. Barrett and Marion Littleton Meeks and John C. Henry},
Existence of oh in interstellar medium, detected in radio absorption spectrum of cassiopeia-a 

Masers in the Interstellar Medium

The basic concepts that govern the production and propagation of maser radiation in interstellar space are introduced and discussed. Specific interstellar masers, in particular those in star forming

Radio Observations of the Interstellar OH Line at 1,667 Mc/s

THE first experimental evidence for the presence of 18-cm absorption lines of the hydroxyl (OH) radical in the radio absorption spectrum of Cassiopeia A, as suggested by Lilley1, was obtained by

Molecular excitation and galactic interstellar clouds

A simplified account of the determination of kinetic temperatures, H2 densities and column densities is given, with emphasis on quasi-thermal excitation. Some examples of the determination of

Anomalous OH absorption in the direction of Cassiopeia A.

Complex OH emission spectra in direction of Cassiopeia A at four ground state frequencies in terms of Zeeman patterns, noting anomalous absorption

A list of interstellar molecules

Interstellar molecules are useful guides to the conditions within interstellar clouds. The list presented here gives information on the sources, abundances and conditions of all interstellar

The relation between interstellar OH and other simple molecules

We discuss the close relation between the column densities of interstellar OH and CH molecules. Our results are obtained on the basis of 10 new sightlines. The OH molecule seems not to be spatially

Interstellar hydroxyl and water masers and formaldehyde masers and dasars

A review of the observational data on anomalous emission by OH, H2O and H2CO molecules and on anomalous absorption by H2CO molecules. Various theories advanced to account for these data and some

Chemical Constituents of Interstellar Clouds

The application of organic chemistry to the interstellar medium has considerably heightened the appreciation of the complexity and variety of interstellar clouds. Results obtained during the past

Angular structure and motions of interstellar masers

A brief historical account is given of the discovery of OH emission and the experiments that led to the identification of the radiation mechanism as maser amplification. An outline is presented of

Ion chemistry in the interstellar medium.

An overview of the interstellar medium, including physical and chemical conditions, spectroscopic observations, and current challenges in characterizing interstellar chemistry is presented, as well as comprehensive summaries of ion-neutral reactions that have been studied since Sablier and Rolando's 1993 review.