A large-scale spectroscopic survey of methanol and oh line emission from the galactic center: Observations and data

W. D. Cotton; F. Yusef-Zadeh

doi:10.3847/0067-0049/227/1/10

A large-scale spectroscopic survey of methanol and oh line emission from the galactic center: Observations and data

W. D. Cotton, F. Yusef-Zadeh

Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

14 Scopus citations

Abstract

Class I methanol masers are collisionally pumped and are generally correlated with outflows in star-forming sites in the Galaxy. Using the Very Large Array in its A-array configuration, we present a spectral line survey to identify methanol J=4_-1 → 3₀E emission at 36.169 GHz. Over 900 pointings were used to cover a region 66′×13′ along the inner Galactic plane. A shallow survey of OH at 1612, 1665, 1667, and 1720 MHz was also carried out over the area covered by our methanol survey. We provide a catalog of 2240 methanol masers with narrow linewidths of ∼1 km s^-1, spatial resolutions of ∼0″.14 × 0″.05, and rms noises ∼20 mJy beam^-1 per channel. Lower limits on the brightness temperature range from 27,000 to 10,000,000 K, showing that the emission is of nonthermal origin. We also provide a list of 23 OH (1612), 14 OH (1665), 5 OH (1667), and 5 OH (1720 MHz) masers. The origin of such a large number of methanol masers is not clear. Many methanol masers appear to be associated with infrared dark clouds, though it appears unlikely that the entire population of these masers traces the early phase of star formation in the Galactic center.

Original language	English (US)
Article number	10
Journal	Astrophysical Journal, Supplement Series
Volume	227
Issue number	1
DOIs	https://doi.org/10.3847/0067-0049/227/1/10
State	Published - Nov 2016

Funding

We wish to acknowledge the numerous helpful comments made by the anonymous reviewer, which led to an improved paper. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc. This work is partially supported by the grant AST-1517246 from the National Science Foundation. This research made use of data products from the Midcourse Space Experiment. Processing of the data was funded by the Ballistic Missile Defense Organization, with additional support from the NASA Office of Space Science. This research has also made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Keywords

Galaxy: center
ISM: clouds
ISM: molecules
ISM: structure

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.3847/0067-0049/227/1/10

Cite this

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title = "A large-scale spectroscopic survey of methanol and oh line emission from the galactic center: Observations and data",

abstract = "Class I methanol masers are collisionally pumped and are generally correlated with outflows in star-forming sites in the Galaxy. Using the Very Large Array in its A-array configuration, we present a spectral line survey to identify methanol J=4-1 → 30E emission at 36.169 GHz. Over 900 pointings were used to cover a region 66′×13′ along the inner Galactic plane. A shallow survey of OH at 1612, 1665, 1667, and 1720 MHz was also carried out over the area covered by our methanol survey. We provide a catalog of 2240 methanol masers with narrow linewidths of ∼1 km s-1, spatial resolutions of ∼0″.14 × 0″.05, and rms noises ∼20 mJy beam-1 per channel. Lower limits on the brightness temperature range from 27,000 to 10,000,000 K, showing that the emission is of nonthermal origin. We also provide a list of 23 OH (1612), 14 OH (1665), 5 OH (1667), and 5 OH (1720 MHz) masers. The origin of such a large number of methanol masers is not clear. Many methanol masers appear to be associated with infrared dark clouds, though it appears unlikely that the entire population of these masers traces the early phase of star formation in the Galactic center.",

keywords = "Galaxy: center, ISM: clouds, ISM: molecules, ISM: structure",

author = "Cotton, {W. D.} and F. Yusef-Zadeh",

year = "2016",

month = nov,

doi = "10.3847/0067-0049/227/1/10",

language = "English (US)",

volume = "227",

journal = "Astrophysical Journal, Supplement Series",

issn = "0067-0049",

publisher = "IOP Publishing Ltd.",

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T1 - A large-scale spectroscopic survey of methanol and oh line emission from the galactic center

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AU - Cotton, W. D.

AU - Yusef-Zadeh, F.

PY - 2016/11

Y1 - 2016/11

N2 - Class I methanol masers are collisionally pumped and are generally correlated with outflows in star-forming sites in the Galaxy. Using the Very Large Array in its A-array configuration, we present a spectral line survey to identify methanol J=4-1 → 30E emission at 36.169 GHz. Over 900 pointings were used to cover a region 66′×13′ along the inner Galactic plane. A shallow survey of OH at 1612, 1665, 1667, and 1720 MHz was also carried out over the area covered by our methanol survey. We provide a catalog of 2240 methanol masers with narrow linewidths of ∼1 km s-1, spatial resolutions of ∼0″.14 × 0″.05, and rms noises ∼20 mJy beam-1 per channel. Lower limits on the brightness temperature range from 27,000 to 10,000,000 K, showing that the emission is of nonthermal origin. We also provide a list of 23 OH (1612), 14 OH (1665), 5 OH (1667), and 5 OH (1720 MHz) masers. The origin of such a large number of methanol masers is not clear. Many methanol masers appear to be associated with infrared dark clouds, though it appears unlikely that the entire population of these masers traces the early phase of star formation in the Galactic center.

AB - Class I methanol masers are collisionally pumped and are generally correlated with outflows in star-forming sites in the Galaxy. Using the Very Large Array in its A-array configuration, we present a spectral line survey to identify methanol J=4-1 → 30E emission at 36.169 GHz. Over 900 pointings were used to cover a region 66′×13′ along the inner Galactic plane. A shallow survey of OH at 1612, 1665, 1667, and 1720 MHz was also carried out over the area covered by our methanol survey. We provide a catalog of 2240 methanol masers with narrow linewidths of ∼1 km s-1, spatial resolutions of ∼0″.14 × 0″.05, and rms noises ∼20 mJy beam-1 per channel. Lower limits on the brightness temperature range from 27,000 to 10,000,000 K, showing that the emission is of nonthermal origin. We also provide a list of 23 OH (1612), 14 OH (1665), 5 OH (1667), and 5 OH (1720 MHz) masers. The origin of such a large number of methanol masers is not clear. Many methanol masers appear to be associated with infrared dark clouds, though it appears unlikely that the entire population of these masers traces the early phase of star formation in the Galactic center.

KW - Galaxy: center

KW - ISM: clouds

KW - ISM: molecules

KW - ISM: structure

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A large-scale spectroscopic survey of methanol and oh line emission from the galactic center: Observations and data

Abstract

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Keywords

ASJC Scopus subject areas

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CH_3_OH & OH line emission from Galactic center

Cite this

A large-scale spectroscopic survey of methanol and oh line emission from the galactic center: Observations and data

Abstract

Funding

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Datasets

CH_3_OH &amp; OH line emission from Galactic center

Cite this

CH_3_OH & OH line emission from Galactic center