EXPANDED VERY LARGE ARRAY DETECTION OF 36.2 GHz CLASS I METHANOL MASERS IN SAGITTARIUS A

Journal Article · Sat Feb 20 04:00:00 EST 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/710/2/L111; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301288

Sjouwerman, Lorant O ^[1]; Pihlstroem, Ylva M ^[2]

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1. National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)
2. Department of Physics and Astronomy, University of New Mexico, 800 Yale Boulevard NE, Albuquerque, NM 87131 (United States)

We report on the interferometric detection of 36.2 GHz Class I methanol emission with the new 27-40 GHz Ka-band receivers available on the Expanded Very Large Array (EVLA). The brightness temperatures of the interferometric 36 GHz detections unambiguously indicate for the first time that the emission is maser emission. The 36 GHz methanol masers are not co-spatial with 1720 MHz OH masers, indicating that the two species trace different shocks. The 36 GHz and 44 GHz methanol masers, which are collisionally pumped, do not necessarily co-exist and may trace different methanol gas. The methanol masers seem correlated with NH{sub 3}(3,3) density peaks. We favor an explanation in which the 36 GHz Class I methanol masers outline regions of cloud-cloud collisions, perhaps just before the onset of the formation of individual massive stars. The transition of the Very Large Array (VLA) to the EVLA is well under way, and these detections demonstrate the bright future of this completely renewed instrument.

• OSTI ID: 21301288
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 710; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
AMMONIA
BRIGHTNESS
GALAXIES
GHZ RANGE 01-100
MASERS
METHANOL
SUPERNOVA REMNANTS