AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region
We present position-velocity strip maps of the Galactic Center region in the CO J=7-6 and J=4-3 transitions observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) located at Amundsen-Scott South Pole Station. Emission from the two rotational transitions of 12^CO was mapp...
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ftcern:oai:cds.cern.ch:573587 2023-05-15T13:24:29+02:00 AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region Kim, S Martin, C L Stark, A A Lane, A P 2002-07-26 http://cds.cern.ch/record/573587 eng eng http://cds.cern.ch/record/573587 astro-ph/0207586 oai:cds.cern.ch:573587 Astrophysics and Astronomy 2002 ftcern 2018-07-28T05:37:51Z We present position-velocity strip maps of the Galactic Center region in the CO J=7-6 and J=4-3 transitions observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) located at Amundsen-Scott South Pole Station. Emission from the two rotational transitions of 12^CO was mapped at b=0 deg for 3.5 deg > l > -1.5 deg, on a 1' grid with a FWHM beamsize of 58'' at 806 GHz and 105'' at 461 GHz. Previous observations of CO J=4-3 (Martin et al., in preparation) and CI (Ojha et al. 2001) emission from this region show that these lines are distributed in a manner similar to CO J=1-0 (Stark et al. 1987); the (CO J=4-3)/(CO J=1-0) line ratio map is almost featureless across the entire Galactic Center region. In contrast, the CO J=7-6 emission from the Galactic Center is strongly peaked toward the Sgr A and Sgr B molecular complexes. A Large Velocity Gradient (LVG) analysis shows that aside from the two special regions Sgr A and Sgr B, the photon-dominated regions within a few hundred parsecs of the Galactic Center are remarkably uniform in mean density and kinetic temperature at n = 2500 to 4000 cm^{-3} and T=30 to 45K. The (CO J=7-6)/(CO J=4-3) line temperature ratios near Sgr B are a factor of two higher than those observed in the nuclear region of the starburst galaxy M82 (Mao et al. 2000), while the CO(J=7-6)/CO(J=4-3) line temperature ratios around Sgr A are similar to M82. The line ratio on large scales from the Galactic Center region is an order of magnitude less than that from M82. Other/Unknown Material Amundsen-Scott Antarc* Antarctic South pole South pole CERN Document Server (CDS) Amundsen Scott South Pole Station ENVELOPE(0.000,0.000,-90.000,-90.000) Amundsen-Scott ENVELOPE(0.000,0.000,-90.000,-90.000) Amundsen-Scott South Pole Station ENVELOPE(139.273,139.273,-89.998,-89.998) Antarctic South Pole The Antarctic |
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Open Polar |
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CERN Document Server (CDS) |
op_collection_id |
ftcern |
language |
English |
topic |
Astrophysics and Astronomy |
spellingShingle |
Astrophysics and Astronomy Kim, S Martin, C L Stark, A A Lane, A P AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region |
topic_facet |
Astrophysics and Astronomy |
description |
We present position-velocity strip maps of the Galactic Center region in the CO J=7-6 and J=4-3 transitions observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) located at Amundsen-Scott South Pole Station. Emission from the two rotational transitions of 12^CO was mapped at b=0 deg for 3.5 deg > l > -1.5 deg, on a 1' grid with a FWHM beamsize of 58'' at 806 GHz and 105'' at 461 GHz. Previous observations of CO J=4-3 (Martin et al., in preparation) and CI (Ojha et al. 2001) emission from this region show that these lines are distributed in a manner similar to CO J=1-0 (Stark et al. 1987); the (CO J=4-3)/(CO J=1-0) line ratio map is almost featureless across the entire Galactic Center region. In contrast, the CO J=7-6 emission from the Galactic Center is strongly peaked toward the Sgr A and Sgr B molecular complexes. A Large Velocity Gradient (LVG) analysis shows that aside from the two special regions Sgr A and Sgr B, the photon-dominated regions within a few hundred parsecs of the Galactic Center are remarkably uniform in mean density and kinetic temperature at n = 2500 to 4000 cm^{-3} and T=30 to 45K. The (CO J=7-6)/(CO J=4-3) line temperature ratios near Sgr B are a factor of two higher than those observed in the nuclear region of the starburst galaxy M82 (Mao et al. 2000), while the CO(J=7-6)/CO(J=4-3) line temperature ratios around Sgr A are similar to M82. The line ratio on large scales from the Galactic Center region is an order of magnitude less than that from M82. |
author |
Kim, S Martin, C L Stark, A A Lane, A P |
author_facet |
Kim, S Martin, C L Stark, A A Lane, A P |
author_sort |
Kim, S |
title |
AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region |
title_short |
AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region |
title_full |
AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region |
title_fullStr |
AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region |
title_full_unstemmed |
AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region |
title_sort |
ast/ro observations of co j=7-6 and j=4-3 emission toward the galactic center region |
publishDate |
2002 |
url |
http://cds.cern.ch/record/573587 |
long_lat |
ENVELOPE(0.000,0.000,-90.000,-90.000) ENVELOPE(0.000,0.000,-90.000,-90.000) ENVELOPE(139.273,139.273,-89.998,-89.998) |
geographic |
Amundsen Scott South Pole Station Amundsen-Scott Amundsen-Scott South Pole Station Antarctic South Pole The Antarctic |
geographic_facet |
Amundsen Scott South Pole Station Amundsen-Scott Amundsen-Scott South Pole Station Antarctic South Pole The Antarctic |
genre |
Amundsen-Scott Antarc* Antarctic South pole South pole |
genre_facet |
Amundsen-Scott Antarc* Antarctic South pole South pole |
op_relation |
http://cds.cern.ch/record/573587 astro-ph/0207586 oai:cds.cern.ch:573587 |
_version_ |
1766379936045596672 |