New interstellar masers in nonmetastable ammonia

Journal Article · Wed Jan 15 04:00:00 EST 1986 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/184607· OSTI ID:6060198

Madden, S C; Irvine, W M; Matthews, H E; Brown, R D; Godfrey, P D

We report the first astronomical detections of several ammonia inversion transitions involving nonmetastable levels with energies as high as 1090 K above the ground state. The (J,K) = (9,6) inversion transition shows maser-like emission in the directions of W51,NGC 7538, W49, and DR 21(OH). The NH/sub 3/ (6,3) line exhibits similar characteristics in W51 but is seen in absorption in NGC 7538. These are the first definite detections of ammonia masers in space. The intensities and narrow line widths (0.5--1.5 km s/sup -1/) for the emission features are in contrast to the previously detected broad, weak, nonmetastable lines attributed to thermal emission in these sources. Temporal variability appears to be evident in the (9,6) emission in W49 over a 4 month period. The highly excited (J,K) = (9,6) and (6,3) ammonia lines are found in regions containing compact H II regions and strong infrared sources with associated H/sub 2/O and OH masers; i.e., in regions of active star formation.

• Research Organization: Department of Physics and Astronomy and Five College Radio Astronomy Observatory, University of Massachusetts
• OSTI ID: 6060198
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 300:2; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
AMPLIFIERS
CHEMISTRY
COSMOCHEMISTRY
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
HYDRIDES
HYDROGEN COMPOUNDS
INTERSTELLAR SPACE
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
MICROWAVE RADIATION
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
RADIATIONS
SPACE
STAR EVOLUTION
TEMPERATURE MEASUREMENT
VELOCITY