Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002apj...580..896k&link_type=abstract
The Astrophysical Journal, Volume 580, Issue 2, pp. 896-903.
Astronomy and Astrophysics
Astronomy
19
Galaxy: Abundances, Galaxy: Center, Ism: General, Ism: Molecules, Submillimeter
Scientific paper
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 located at the Amundsen-Scott South Pole Station. Emission from the two rotational transitions of 12CO was mapped at b=0deg for 3.5d>l>-1.5d on a 1' grid with a FWHM beam size of 58" at 806 GHz and 105" at 461 GHz. Previous observations of CO J=4-->3 (C. L. Martin et al., in preparation) and of [C I] emission (Ojha et al.) from this region show that these lines are distributed in a manner similar to CO J=1-->0 (Stark et al.); 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 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=2500-4000 cm-3 and T=30-45 K. The (CO J=7-->6)/(CO J=4-->3) line temperature ratios near Sgr B are a factor of 2 higher than those observed in the nuclear region of the starburst galaxy M82 (Mao et al.), 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.
Kim Sunguen
Lane Adair P.
Martin Christopher L.
Stark Antony A.
No associations
LandOfFree
Antarctic Submillimeter Telescope and Remote Observatory Observations of CO J=7-->6 and J=4-->3 Emission toward the Galactic Center Region does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Antarctic Submillimeter Telescope and Remote Observatory Observations of CO J=7-->6 and J=4-->3 Emission toward the Galactic Center Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antarctic Submillimeter Telescope and Remote Observatory Observations of CO J=7-->6 and J=4-->3 Emission toward the Galactic Center Region will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1440850