TY - JOUR
T1 - Formation of the Active Star-forming Region LHA 120-N 44 Triggered by Tidally Driven Colliding Hi Flows
AU - Tsuge, Kisetsu
AU - Sano, Hidetoshi
AU - Tachihara, Kengo
AU - Yozin, Cameron
AU - Bekki, Kenji
AU - Inoue, Tsuyoshi
AU - Mizuno, Norikazu
AU - Kawamura, Akiko
AU - Onishi, Toshikazu
AU - Fukui, Yasuo
PY - 2019/1/20
Y1 - 2019/1/20
N2 -
The second most active site of high-mass star formation next to R136 in the Large Magellanic Cloud (LMC) is N44. We carried out a detailed analysis of H i at 60″ resolution by using the ATCA and Parkes data. We presented decomposition of the H i emission into two velocity components (the L and D components) with a velocity separation of ∼60 km s
-1
. In addition, we newly defined the I component whose velocity is intermediate between the L and D components. The D component was used to derive the rotation curve of the LMC disk, which is consistent with the stellar rotation curve. Toward the active cluster-forming region of LHA 120-N 44, the three velocity components of H i gas show signatures of dynamical interaction, including bridges and complementary spatial distributions. We hypothesize that the L and D components have been colliding with each other since 5 Myr ago, and the interaction triggered formation of the O and early-B stars ionizing N44. In the hypothesis, the I component is interpreted as decelerated gas in terms of momentum exchange in the collisional interaction of the L and D components. In the N44 region, the Planck submillimeter dust optical depth is correlated with the H i intensity, which is well approximated by a linear regression. We found that the N44 region shows a significantly steeper regression line than in the bar region, indicating less dust abundance in the N44 region, which is ascribed to the tidal interaction between the LMC and the SMC 0.2 Gyr ago.
AB -
The second most active site of high-mass star formation next to R136 in the Large Magellanic Cloud (LMC) is N44. We carried out a detailed analysis of H i at 60″ resolution by using the ATCA and Parkes data. We presented decomposition of the H i emission into two velocity components (the L and D components) with a velocity separation of ∼60 km s
-1
. In addition, we newly defined the I component whose velocity is intermediate between the L and D components. The D component was used to derive the rotation curve of the LMC disk, which is consistent with the stellar rotation curve. Toward the active cluster-forming region of LHA 120-N 44, the three velocity components of H i gas show signatures of dynamical interaction, including bridges and complementary spatial distributions. We hypothesize that the L and D components have been colliding with each other since 5 Myr ago, and the interaction triggered formation of the O and early-B stars ionizing N44. In the hypothesis, the I component is interpreted as decelerated gas in terms of momentum exchange in the collisional interaction of the L and D components. In the N44 region, the Planck submillimeter dust optical depth is correlated with the H i intensity, which is well approximated by a linear regression. We found that the N44 region shows a significantly steeper regression line than in the bar region, indicating less dust abundance in the N44 region, which is ascribed to the tidal interaction between the LMC and the SMC 0.2 Gyr ago.
KW - (galaxies:) Magellanic Clouds
KW - galaxies: ISM
KW - galaxies: star formation
KW - H II regions
KW - ISM: atoms
KW - stars: massive
UR - http://www.scopus.com/inward/record.url?scp=85062028278&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aaf4fb
DO - 10.3847/1538-4357/aaf4fb
M3 - Article
AN - SCOPUS:85062028278
VL - 871
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 44
ER -