TY - JOUR
T1 - HIGH-MASS STAR FORMATION TRIGGERED BY COLLISION BETWEEN CO FILAMENTS IN N159 WEST IN THE LARGE MAGELLANIC CLOUD
AU - Fukui, Yasuo
AU - Harada, Ryohei
AU - Tokuda, Kazuki
AU - Morioka, Yuuki
AU - Onishi, Toshikazu
AU - Torii, Kazufumi
AU - Ohama, Akio
AU - Hattori, Yusuke
AU - Nayak, Omnarayani
AU - Meixner, Margaret
AU - Sewiło, Marta
AU - Indebetouw, Remy
AU - Kawamura, Akiko
AU - Saigo, Kazuya
AU - Yamamoto, Hiroaki
AU - Tachihara, Kengo
AU - Minamidani, Tetsuhiro
AU - Inoue, Tsuyoshi
AU - Madden, Suzanna
AU - Galametz, Maud
AU - Lebouteiller, Vianney
AU - Mizuno, Norikazu
AU - Chen, C. H.Rosie
N1 - Publisher Copyright:
© 2015. The American Astronomical Society. All rights reserved.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - We have carried out 13CO(J = 2-1) observations of the active star-forming region N159 west in the Large Magellanic Cloud with ALMA. We have found that the CO distribution at a sub-parsec scale is highly elongated with a small width. These elongated clouds called "filaments" show straight or curved distributions with a typical width of 0.5-1.0 pc and a length of 5-10 pc. All the known infrared young stellar objects are located toward the filaments. We have found broad CO wings of two molecular outflows toward young high-mass stars in N159W-N and N159W-S, whose dynamical timescale is ∼104 years. This is the first discovery of protostellar outflow in external galaxies. For N159W-S, which is located toward an intersection of two filaments, we set up a hypothesis that the two filaments collided with each other ∼105 years ago and triggered the formation of the high-mass star having ∼37 M⊙. The colliding clouds show significant enhancement in linewidth in the intersection, suggesting excitation of turbulence in the shocked interface layer between them, as is consistent with the magnetohydrodynamical numerical simulations. This turbulence increases the mass accretion rate to ∼6 × 10-4 M⊙ yr-1, which is required to overcome the stellar feedback to form the high-mass star.
AB - We have carried out 13CO(J = 2-1) observations of the active star-forming region N159 west in the Large Magellanic Cloud with ALMA. We have found that the CO distribution at a sub-parsec scale is highly elongated with a small width. These elongated clouds called "filaments" show straight or curved distributions with a typical width of 0.5-1.0 pc and a length of 5-10 pc. All the known infrared young stellar objects are located toward the filaments. We have found broad CO wings of two molecular outflows toward young high-mass stars in N159W-N and N159W-S, whose dynamical timescale is ∼104 years. This is the first discovery of protostellar outflow in external galaxies. For N159W-S, which is located toward an intersection of two filaments, we set up a hypothesis that the two filaments collided with each other ∼105 years ago and triggered the formation of the high-mass star having ∼37 M⊙. The colliding clouds show significant enhancement in linewidth in the intersection, suggesting excitation of turbulence in the shocked interface layer between them, as is consistent with the magnetohydrodynamical numerical simulations. This turbulence increases the mass accretion rate to ∼6 × 10-4 M⊙ yr-1, which is required to overcome the stellar feedback to form the high-mass star.
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U2 - 10.1088/2041-8205/807/1/L4
DO - 10.1088/2041-8205/807/1/L4
M3 - Article
AN - SCOPUS:84934274737
SN - 2041-8205
VL - 807
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L4
ER -