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Title: NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538

Abstract

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.

Authors:
;  [1]
  1. St. Paul's School, Concord, NH 03301 (United States)
Publication Date:
OSTI Identifier:
21565448
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 739; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/739/1/L15; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMMONIA; EMISSION; MASERS; NEBULAE; AMPLIFIERS; ELECTRONIC EQUIPMENT; EQUIPMENT; HYDRIDES; HYDROGEN COMPOUNDS; MICROWAVE AMPLIFIERS; MICROWAVE EQUIPMENT; NITROGEN COMPOUNDS; NITROGEN HYDRIDES

Citation Formats

Hoffman, Ian M., and Kim, Stella Seojin, E-mail: ihoffman@sps.edu. NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538. United States: N. p., 2011. Web. doi:10.1088/2041-8205/739/1/L15.
Hoffman, Ian M., & Kim, Stella Seojin, E-mail: ihoffman@sps.edu. NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538. United States. doi:10.1088/2041-8205/739/1/L15.
Hoffman, Ian M., and Kim, Stella Seojin, E-mail: ihoffman@sps.edu. Tue . "NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538". United States. doi:10.1088/2041-8205/739/1/L15.
@article{osti_21565448,
title = {NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538},
author = {Hoffman, Ian M. and Kim, Stella Seojin, E-mail: ihoffman@sps.edu},
abstractNote = {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.},
doi = {10.1088/2041-8205/739/1/L15},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 739,
place = {United States},
year = {2011},
month = {9}
}