Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2010-02-08
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
10 pages, 6 figures, Proceedings of the Galactic Center Workshop 2009, Shanghai
Scientific paper
Large-scale CO surveys have revealed that the central molecular zone (CMZ) of our Galaxy is characterized by a number of expanding shells/arcs, and by a peculiar population of compact clouds with large velocity widths -- high-velocity compact clouds (HVCCs). We have performed a large-scale CO J=3-2 survey of the CMZ from 2005 to 2008 with the Atacama Submillimeter-wave Telescope Experiment (ASTE). The data cover almost the full extent of the CMZ and the Clump 2 with a 34 arcsec grid spacing. The CO J=3-2 data were compared with the CO J=1--0 data taken with the Nobeyama Radio Observatory 45 m telescope. Molecular gas in the CMZ exhibits higher J=3-2/J=1-0 intensity ratios [R(3-2/1-0)=0.7] than that in the Galactic disk [R(3-2/1-0)=0.4]. We extracted highly excited, optically thin gas by the criterion, R(3-2/1-0)>=1.5. Clumps of high R(3-2/1-0) gas were found in the Sgr A and Sgr C regions, near SNR G 0.9+0.1, and three regions with energetic HVCCs; CO 1.27+0.01, CO -0.41-0.23, and CO -1.21-0.12. We also found a number of small spots of high R(3-2/1-0) gas over the CMZ. Many of these high R(3-2/1-0) clumps and spots have large velocity widths, and some apparently coincides with HVCCs, suggesting that they are spots of shocked molecular gas. Their origin should be local explosive events, possibly supernova explosions. These suggest that the energetic HVCCs are associated with massive compact clusters, which have been formed by microbursts of star formation. Rough estimates of the energy flow from large to small scale suggest that the supernova shocks can make a significant contribution to turbulence activation and gas heating in the CMZ.
Hasegawa Tetsuo
Kamegai Kazuhisa
Matsumura Shinji
Nagai Makoto
Oka Tomoharu
No associations
LandOfFree
The ASTE Galactic Center CO J=3-2 Survey: Probing Shocked Molecular Gas in the CMZ 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 The ASTE Galactic Center CO J=3-2 Survey: Probing Shocked Molecular Gas in the CMZ, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The ASTE Galactic Center CO J=3-2 Survey: Probing Shocked Molecular Gas in the CMZ will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-307699