72 research outputs found
A Spectral Line Survey of Selected 3 mm Bands Toward Sagittarius B2(N-LMH) Using the NRAO 12 Meter Radio Telescope and the BIMA Array I. The Observational Data
We have initiated a spectral line survey, at a wavelength of 3 millimeters,
toward the hot molecular core Sagittarius B2(N-LMH). This is the first spectral
line survey of the Sgr B2(N) region utilizing data from both an interferometer
(BIMA Array) and a single-element radio telescope (NRAO 12 meter). In this
survey, covering 3.6 GHz in bandwidth, we detected 218 lines (97 identified
molecular transitions, 1 recombination line, and 120 unidentified transitions).
This yields a spectral line density (lines per 100 MHz) of 6.06, which is much
larger than any previous 3 mm line survey. We also present maps from the BIMA
Array that indicate that most highly saturated species (3 or more H atoms) are
products of grain chemistry or warm gas phase chemistry. Due to the nature of
this survey we are able to probe each spectral line on multiple spatial scales,
yielding information that could not be obtained by either instrument alone.Comment: 35 pages, 15 figures, to be published in The Astrophysical Journa
NEW SUBMILLIMETER CW LASER LINES IN OPTICALLY PUMPED GAS MOLECULES -- ASSIGNMENT OF THE FORMIC ACID LASER
Author Institution: Laboratoire de Spectroscopie Hertzienne, Universit\'{e} de LilleA submillimeter laser optically pumped by a laser has been built and cw laser action has been observed from 1033 to 195 in several molecules: , HDCO, , DCOOD, , HCOOD. In the case of the accurate measurements of 18 cw laser lines from 380 to 1000 GHz has been performed by measuring the beat notes of the mixing of the harmonics of a phase locked millimeter source with the laser emission. The accuracy of the measurements is about 0.5 to 1 MHz. The assignment of the formic acid laser lines needs detailed spectra of ground and vibrationally excited states. The ground state is well known. An experimental improvement of the pure rotational spectra of the and vibrationally excited states has been necessary. The pumping is performed from ground state levels up to excited states. Most of the laser emission lines have been assigned to the excited state; it is thus possible to derive a very good value for the band center of this state."
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