NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538

Journal Article · Tue Sep 20 04:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/739/1/L15· OSTI ID:21565448

Hoffman, Ian M

We present the first interferometric observations at 18.5 GHz of IRS 1 in NGC 7538. These observations include images of the nonmetastable {sup 14}NH{sub 3} (9, 6) masers with a synthesized beam of 2 arcsec and images of the continuum emission with a synthesized beam of 150 mas. Of the maser emission, the previously known feature near v {sub LSR} = -60 km s{sup -1} is spectrally resolved into at least two components and we observe several new maser emission features near v {sub LSR} = -57 km s{sup -1}. The new maser emission near -57 km s{sup -1} lies 250 {+-} 90 mas northwest of the maser emission near -60 km s{sup -1}. All of the masers are angularly unresolved indicating brightness temperatures T{sub B} > 2000 K. We are also able to conclusively associate the ammonia masers with the position of IRS 1. The excitation of these rare ammonia masers is discussed in the context of the rich maser environment of IRS 1.

• OSTI ID: 21565448
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 739; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AMMONIA
AMPLIFIERS
ELECTRONIC EQUIPMENT
EMISSION
EQUIPMENT
HYDRIDES
HYDROGEN COMPOUNDS
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NEBULAE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES