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

  title={Radio Observations of the Interstellar OH Line at 1,667 Mc/s},
  author={Nannielou H. Dieter and Harold I. Ewen},
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 Weinreb et al.2 based on observations made during the period October 15–29, 1963. The Radio Physics Laboratory, Commonwealth Scientific and Industrial Research Organization, in Sydney, Australia, has reported the successful measurement of OH absorption in the spectrum of Sagittarius (see preceding… 

Radio Observations of Interstellar Hydroxyl Radicals

The discovery of the radio frequency lines of OH gave the first positive evidence of the existence of OH in the interstellar medium, but many observations have revealed totally unexpected anomalies in the radio-spectral properties of interstellar OH.

OH Absorption Spectra in Sagittarius

WE have measured the 18-cm OH absorption spectrum of Sagittarius A over a range of 6.4 Mc/s using the 60-ft. radio telescope of Harvard College Observatory. This frequency range covers both the 1,667

The Detection of the OH and Other Molecular Lines in the Radio Spectrum of the Interstellar Medium

  • A. H. Barrett
  • Physics
    IEEE Transactions on Military Electronics
  • 1964
The detection of the 2П3/2, J= 3/2 Λ-doublet lines of O16H1 at 1665.36 Mc and 1667.40 Mc has provided radio astronomy with a second spectral line for investigation and has already given rise to a

High-resolution Microwave Spectra of H and OH Absorption Lines of Cassiopeia A

IN a recent communication Weinreb, Barrett, Meeks and Henry1 reported the discovery of the 18-cm lines of the hydroxyl (OH) radical in the radio absorption spectra of Cassiopeia A, and the result was

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

The Central 300 pc of the Galaxy Probed by Infrared Spectra of H3 + and CO. II. Expansion and Morphology of the Warm Diffuse Gas

Velocity profiles of a line of at 3.7 μm produced in warm diffuse gas have been observed toward 18 stars in the Central Molecular Zone (CMZ) of the Galaxy. Their longitude–velocity diagram indicates

VUV photochemistry and nuclear spin conversion of water and water-orthohydrogen complexes in parahydrogen crystals at 4 K.

The observed temporal changes in concentrations, especially the increase of HDO concentration during VUV irradiation, can be interpreted by a model with a rapid conversion from orthohydrogen (oH2) to pH2 in water-o H2 complexes upon VUV photodissociation.

Three-dimensional molecular line transfer: A simulated star-forming region

We present the first non-local thermodynamic equilibrium (non-LTE), comoving frame molecular line calculations of a star-forming cluster simulated using smoothed particle hydrodynamics (SPH), from

Hydroxyl radicals via collision-induced dissociation of trimethylammonium benzyl alcohols

The observation that trimethylammonium benzyl alcohols and their corresponding deuterated isotopologues act as a good source of hydroxyl and deuteroxyl radicals in the gas-phase under collision-induced dissociation (CID) conditions is reported.