A CO J = 3-2 survey of the galactic center

Tomoharu Oka; Makoto Nagai; Kazuhisa Kamegai; Kunihiko Tanaka; Nobuyuki Kuboi

doi:10.1093/pasj/59.1.15

A CO J = 3-2 survey of the galactic center

Tomoharu Oka, Makoto Nagai, Kazuhisa Kamegai, Kunihiko Tanaka, Nobuyuki Kuboi

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64 Citations (Scopus)

Abstract

We have surveyed the central molecular zone (CMZ) of our Galaxy in the CO J = 3-2 line with the Atacama Submillimeter-wave Telescope Experiment (ASTE). Molecular gas in the Galactic center shows a high J=3-2/J=1-0 intensity ratio (∼ 0.9), while gas in the spiral arms of the Galactic disk shows a lower ratio (∼ 0.5). The high-velocity compact cloud CO 0.02-0.02 and the hyperenergetic shell CO 1.27+0.01, as well as gas in the Sgr A region, exhibit high J=3-2/J=1-0 intensity ratios exceeding 1.5. We also found a number of small spots of high-ratio gas. Some of these high-ratio spots have large velocity widths and some seem to be associated with nonthermal threads or filaments. These could be spots of hot molecular gas shocked by unidentified supernovae, which may be abundant in the CMZ.

Original language	English
Pages (from-to)	15-23
Number of pages	9
Journal	Publications of the Astronomical Society of Japan
Volume	59
Issue number	1
DOIs	https://doi.org/10.1093/pasj/59.1.15
Publication status	Published - 2007
Externally published	Yes

Keywords

Galaxies: nuclei
Galaxy: center
ISM: clouds
ISM: molecules

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1093/pasj/59.1.15

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title = "A CO J = 3-2 survey of the galactic center",

abstract = "We have surveyed the central molecular zone (CMZ) of our Galaxy in the CO J = 3-2 line with the Atacama Submillimeter-wave Telescope Experiment (ASTE). Molecular gas in the Galactic center shows a high J=3-2/J=1-0 intensity ratio (∼ 0.9), while gas in the spiral arms of the Galactic disk shows a lower ratio (∼ 0.5). The high-velocity compact cloud CO 0.02-0.02 and the hyperenergetic shell CO 1.27+0.01, as well as gas in the Sgr A region, exhibit high J=3-2/J=1-0 intensity ratios exceeding 1.5. We also found a number of small spots of high-ratio gas. Some of these high-ratio spots have large velocity widths and some seem to be associated with nonthermal threads or filaments. These could be spots of hot molecular gas shocked by unidentified supernovae, which may be abundant in the CMZ.",

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author = "Tomoharu Oka and Makoto Nagai and Kazuhisa Kamegai and Kunihiko Tanaka and Nobuyuki Kuboi",

year = "2007",

doi = "10.1093/pasj/59.1.15",

language = "English",

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T1 - A CO J = 3-2 survey of the galactic center

AU - Oka, Tomoharu

AU - Nagai, Makoto

AU - Kamegai, Kazuhisa

AU - Tanaka, Kunihiko

AU - Kuboi, Nobuyuki

PY - 2007

Y1 - 2007

N2 - We have surveyed the central molecular zone (CMZ) of our Galaxy in the CO J = 3-2 line with the Atacama Submillimeter-wave Telescope Experiment (ASTE). Molecular gas in the Galactic center shows a high J=3-2/J=1-0 intensity ratio (∼ 0.9), while gas in the spiral arms of the Galactic disk shows a lower ratio (∼ 0.5). The high-velocity compact cloud CO 0.02-0.02 and the hyperenergetic shell CO 1.27+0.01, as well as gas in the Sgr A region, exhibit high J=3-2/J=1-0 intensity ratios exceeding 1.5. We also found a number of small spots of high-ratio gas. Some of these high-ratio spots have large velocity widths and some seem to be associated with nonthermal threads or filaments. These could be spots of hot molecular gas shocked by unidentified supernovae, which may be abundant in the CMZ.

AB - We have surveyed the central molecular zone (CMZ) of our Galaxy in the CO J = 3-2 line with the Atacama Submillimeter-wave Telescope Experiment (ASTE). Molecular gas in the Galactic center shows a high J=3-2/J=1-0 intensity ratio (∼ 0.9), while gas in the spiral arms of the Galactic disk shows a lower ratio (∼ 0.5). The high-velocity compact cloud CO 0.02-0.02 and the hyperenergetic shell CO 1.27+0.01, as well as gas in the Sgr A region, exhibit high J=3-2/J=1-0 intensity ratios exceeding 1.5. We also found a number of small spots of high-ratio gas. Some of these high-ratio spots have large velocity widths and some seem to be associated with nonthermal threads or filaments. These could be spots of hot molecular gas shocked by unidentified supernovae, which may be abundant in the CMZ.

KW - Galaxies: nuclei

KW - Galaxy: center

KW - ISM: clouds

KW - ISM: molecules

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DO - 10.1093/pasj/59.1.15

M3 - Article

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SN - 0004-6264

VL - 59

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EP - 23

JO - Publication of the Astronomical Society of Japan

JF - Publication of the Astronomical Society of Japan

IS - 1

ER -

A CO J = 3-2 survey of the galactic center

Abstract

Keywords

ASJC Scopus subject areas

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