Observations of quasi-thermal and maser phenomena in rotationally excited OH. I.

Journal Article · Fri Aug 15 04:00:00 EDT 1975 · Astrophys. J., v. 200, no. 1, pp. 6-21

DOI:https://doi.org/10.1086/153755· OSTI ID:4161464

Rickard, L J; Zuckerman, B; Palmer, P

Absorption features arising from $lambda$-doublet transitions in a very short-lived rotationally excited state of OH have been discovered in the direction of the W3 continuum peak. Analyses of these features and of broad emission features in Sgr indicate the presence of massive regions with very high densities. An extensive search for new sources of maser emission from excited- state OH has resulted in the detection of maser features in NGC 7538, OH 69.5-- 1.0, M17, W51, and Orion (OH). Observations with circular polarization suggest Zeeman effects in some spectra, with inferred magnetic field strengths of several milligauss. A rapid time variation has been observed in the maser spectrum of Sgr B2, and evidence is presented for variations in W51 and W3 (continuum).

• Research Organization: University of Chicago
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-003843
• OSTI ID: 4161464
• Journal Information: Astrophys. J., v. 200, no. 1, pp. 6-21, Journal Name: Astrophys. J., v. 200, no. 1, pp. 6-21; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

*COSMIC GASES-- EXCITATION
640105* --Physics Research--Astrophysics & Cosmology-- Galaxies
HYDROXYL RADICALS
INFRARED RADIATION
INTERSTELLAR SPACE
MOLECULES
N56500* --Physics (Astrophysics & Cosmology)--Galaxies
POLARIZATION
ROTATIONAL STATES
VARIATIONS