Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2010-11-29
A&A 2011, 525, 8
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
13 pages, 10 figures, accepted for publication by A&A
Scientific paper
10.1051/0004-6361/201014765
Aims: We aim at deriving the excitation conditions of the interstellar gas as well as the local FUV intensities in the molecular cloud surrounding NGC 3603 to get a coherent picture of how the gas is energized by the central stars. Methods: The NANTEN2-4m submillimeter antenna is used to map the [CI] 1-0, 2-1 and CO 4-3, 7-6 lines in a 2' x 2' region around the young OB cluster NGC 3603 YC. These data are combined with C18O 2-1 data, HIRES-processed IRAS 60 and 100 micron maps of the FIR continuum, and Spitzer/IRAC maps. Results: The NANTEN2 observations show the presence of two molecular clumps located south-east and south-west of the cluster and confirm the overall structure already found by previous CS and C18O observations. We find a slight position offset of the peak intensity of CO and [CI], and the atomic carbon appears to be further extended compared to the molecular material. We used the HIRES far-infrared dust data to derive a map of the FUV field heating the dust. We constrain the FUV field to values of \chi = 3 - 6 \times 10^3 in units of the Draine field across the clouds. Approximately 0.2 to 0.3 % of the total FUV energy is re-emitted in the [CII] 158 {\mu}m cooling line observed by ISO. Applying LTE and escape probability calculations, we derive temperatures (TMM1 = 43 K, TMM2 = 47 K), column densities (N(MM1) = 0.9 \times 10^22 cm^-2, N(MM2) = 2.5 \times 10^22 cm^-2) and densities (n(MM1) = 3 \times 10^3 cm^-3, n(MM2) = 10^3 -10^4 cm^-3) for the two observed molecular clumps MM1 and MM2. Conclusions: The cluster is strongly interacting with the ambient molecular cloud, governing its structure and physical conditions. A stability analysis shows the existence of gravitationally collapsing gas clumps which should lead to star formation. Embedded IR sources have already been observed in the outskirts of the molecular cloud and seem to support our conclusions.
Aravena Manuel
Bensch Frank
Bertoldi Frank
Bronfman Leonard
Cubick Markus
No associations
LandOfFree
Photon Dominated Regions in NGC 3603 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 Photon Dominated Regions in NGC 3603, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photon Dominated Regions in NGC 3603 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-221631