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Matthews, H. E.

Publications and source records attributed to Matthews, H. E..

23 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

The hydrocarbon ring C3H2 is ubiquitous in the Galaxy

The discovery of a strong microwave (1.6 cm-wavelength) spectral line, the carrier of which is common and widespread throughout the Galaxy is reported. A survey of a large number of sources shows that the line appears in emission in cold dust clouds, in absorption in the direction of the Galactic center, and exhibits complex profiles toward H II regions. Toward Cas A and distant H II regions, intervening 'spiral arm' clouds produce absorption. For almost all cases, the absorption features show a striking 1:1 radial velocity correspondence with those seen, e.g., in H2CO spectra of the same objects. The data indicate that the line arises between low-lying energy states of a rather polar molecule. Recent work by Thaddeus, Vrtilek, and Gottlieb (1985) incorporating the present data, shows that the line in question is the 1(10)-1(01) transition of the small hydrocarbon ring C3H2.

Matthews, H. E.↗
NASA NTRS1985

The detection of acetaldehyde in cold dust clouds

Observations of the 1(01)-0(00) rotational transitions of A and E state acetaldehyde are reported. The transitions were detected, for the first time in interstellar space, in the cold dust clouds TMC-1 and L134N, and in Sgr B2. This is also the first time acetaldehyde has been found in a dust cloud and is the most complex oxygen-bearing molecule yet known in this environment. A column density of 6 x 10 to the 12th/sq cm in TMC-1, comparable to many other species detected there, and an approximately equal column density in L134N are formed. In the direction of Sgr B2, the CH3CHO profile appears to consist of broad emission features from the hot molecular cloud core, together with absorption features resulting from intervening colder material. The possible detection of HC9N toward IRC + 10 deg 216 through its J = 33-32 transition is also reported. Implications for cold dust cloud chemistry and excitation are discussed.

Matthews, H. E.↗
NASA NTRS1984

A new interstellar molecule - Tricarbon monoxide

The C3O molecule, whose pure rotational spectrum has only recently been studied in the laboratory, has been detected in the cold, dark interstellar Taurus Molecular Cloud 1. Since C3O is the first interstelar carbon chain molecule to contain oxygen, its existence places an important new constraint on chemical schemes for cold interstellar clouds. The abundance of C3O can be understood in terms of purely gas-phase ion-molecule chemistry.

Matthews, H. E.↗