D. Buhl

Radio detection of interstellar sulfur dioxide

Interstellar sulfur dioxide (SO2) has been detected in emission from the direction of the Orion Nebula molecular cloud and from Sgr B2. SO2 is the heaviest interstellar molecule detected to date, and the only nonlinear triatomic molecule which does not contain hydrogen. The remarkable Orion emission profiles suggest that two components are supporting the SO2 emission: a dense circumstellar-type envelope, which may be in maser emission, and a warm galactic cloud component.

An extensive galactic search for conformer II glycine

We have conducted the most extensive galactic search reported to date for conformer II glycine, a higher energy form of the simplest amino acid. The search utilized four glycine transitions at centimeter wavelengths and 21 at millimeter wavelengths to observe 18 galactic molecular sources and one comet. No conformer II glycine lines were detected and measurements of representative sources were used to compute upper limits on total column densities. Several unidentified lines were detected and are reported here with some suggested possible identifications.

Observations of Interstellar Formaldehyde

Rotational transition of interstellar formaldehyde in absorption in direction of galactic and extragalactic objects

Radio detection of interstellar dimethyl ether

The detection of interstellar dimethyl ether, in emission from the direction of the Orion Nebula molecular cloud, is reported. The largest molecule detected in space, dimethyl ether has a large collisional cross section and C (sub 2V) symmetry. Hence, it should be useful for future studies of molecular pumping models.

Millimeter emission lines in Orion A

During the course of a search of Orion A for signals from three large, organic molecules, several millimeter wave lines from known interstellar molecules were observed. Results of observations on methanol (CH/sub 3/OH), methyl cyanide (CH/sub 3/CN), methyl acetylene (CH/sub 3/CCH), acetaldehyde (CH/sub 3/CHO) and /sup 29/SiO are reported here. Emission signals from two hydrogen recombination lines (H41..cap alpha.. and H42..cap alpha..) detected from the H II region of Orion A are also reported. Negative results were obtained for several millimeter wave transitions of ethylene oxide (CH/sub 2/OCH/sub 2/), acetone ((CH/sub 3/)/sub 2/CO), and cyclopropenone (HCCOCH). (AIP)

Radio detection of interstellar DCO/sup +/

The J=1--0 transition of the deuterated formyl ion, DCO/sup +/, has been detected in emission from NGC 2264 and DR 21(OH) and from the cool dust cloud L134. Estimates for the column density ratios of H/sup 13/CO/sup +/ to DCO/sup +/ are given for NGC 2264 and DR 21(OH); lower limits for the ratios are given for five other clouds. The DCO/sup +/ dectection in L134 provides unique observational evidence in support of chemical fractionation. The L134 results also suggest that the dust clouds may act as repositories for primordial deuterium. (AIP)

Interstellar molecules and the origin of life.

Synopsis of the various views expressed at the conference held at NASA Ames Research Center in February 1971 on the relationship of interstellar molecules to the origin of life, intended to provide a basis for future discussion and work in this area. The topics covered include: a summary of molecules discovered, the interstellar environment, laboratory measurements, chemical evolution, and exobiology.

Constraints on the molecular properties of interstellar X-ogen derived from radio observations

Twenty-eight X-ogen emission sources at 89.189 GHz have been detected and observed; of these, 20 are new X-ogen sources which also contain other interstellar molecules. No infrared stars were found to be X-ogen sources. A new rest frequency, 89,188.65 MHz, has been derived for X-ogen. We show that X- ogen is not SiC, C

Is there a maser in the silicon monoxide ground state

sub 2

An investigation of the spectra and time variations of galactic water-vapor sources

H, or any molecule with spin-doubling and/or hyperfine structure. (AIP)