TY - JOUR
T1 - Dense molecular clumps associated with the large magellanic cloud supergiant shells LMC 4 and LMC 5
AU - Fujii, Kosuke
AU - Minamidani, Tetsuhiro
AU - Mizuno, Norikazu
AU - Onishi, Toshikazu
AU - Kawamura, Akiko
AU - Muller, Erik
AU - Dawson, Joanne
AU - Tatematsu, Ken'Ichi
AU - Hasegawa, Tetsuo
AU - Tosaki, Tomoka
AU - Miura, Rie E.
AU - Muraoka, Kazuyuki
AU - Sakai, Takeshi
AU - Tsukagoshi, Takashi
AU - Tanaka, Kunihiko
AU - Ezawa, Hajime
AU - Fukui, Yasuo
N1 - Publisher Copyright:
© 2014. The American Astronomical Society. All rights reserved.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - We investigate the effects of supergiant shells (SGSs) and their interaction on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star-forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC 5. 12CO (J = 3-2, 1-0) and 13CO(J = 1-0) observations with the ASTE and Mopra telescopes have been carried out toward these regions. A clumpy distribution of dense molecular clumps is revealed with 7 pc spatial resolution. Large velocity gradient analysis shows that the molecular hydrogen densities (n(H2)) of the clumps are distributed from low to high density (103-105 cm-3) and their kinetic temperatures (T kin) are typically high (greater than 50 K). These clumps seem to be in the early stages of star formation, as also indicated from the distribution of Hα, young stellar object candidates, and IR emission. We found that the N48 region is located in the high column density H I envelope at the interface of the two SGSs and the star formation is relatively evolved, whereas the N49 region is associated with LMC 5 alone and the star formation is quiet. The clumps in the N48 region typically show high n(H2) and T kin, which are as dense and warm as the clumps in LMC massive cluster-forming areas (30 Dor, N159). These results suggest that the large-scale structure of the SGSs, especially the interaction of two SGSs, works efficiently on the formation of dense molecular clumps and stars.
AB - We investigate the effects of supergiant shells (SGSs) and their interaction on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star-forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC 5. 12CO (J = 3-2, 1-0) and 13CO(J = 1-0) observations with the ASTE and Mopra telescopes have been carried out toward these regions. A clumpy distribution of dense molecular clumps is revealed with 7 pc spatial resolution. Large velocity gradient analysis shows that the molecular hydrogen densities (n(H2)) of the clumps are distributed from low to high density (103-105 cm-3) and their kinetic temperatures (T kin) are typically high (greater than 50 K). These clumps seem to be in the early stages of star formation, as also indicated from the distribution of Hα, young stellar object candidates, and IR emission. We found that the N48 region is located in the high column density H I envelope at the interface of the two SGSs and the star formation is relatively evolved, whereas the N49 region is associated with LMC 5 alone and the star formation is quiet. The clumps in the N48 region typically show high n(H2) and T kin, which are as dense and warm as the clumps in LMC massive cluster-forming areas (30 Dor, N159). These results suggest that the large-scale structure of the SGSs, especially the interaction of two SGSs, works efficiently on the formation of dense molecular clumps and stars.
KW - ISM: bubbles
KW - ISM: clouds
KW - ISM: structure
KW - Magellanic Clouds
KW - galaxies: star formation
KW - radio lines: ISM
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U2 - 10.1088/0004-637X/796/2/123
DO - 10.1088/0004-637X/796/2/123
M3 - Article
AN - SCOPUS:84911169586
VL - 796
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 123
ER -