TY - JOUR
T1 - Explaining the mysterious age gap of globular clusters in the large magellanic cloud
AU - Bekki, Kenji
AU - Couch, Warrick J.
AU - Beasley, Michael A.
AU - Forbes, Duncan A.
AU - Chiba, Masashi
AU - Da Costa, Gary S.
N1 - Funding Information:
We are grateful to the anonymous referee for valuable comments that improved the present Letter. K. B., W. J. C., and G. S. D. acknowledge financial support from the Australian Research Council throughout the course of this work. The numerical simulations reported here were carried out on GRAPE systems kindly made available by the Astronomical Data Analysis Center at the National Astronomical Observatory of Japan.
PY - 2004/8/1
Y1 - 2004/8/1
N2 - The Large Magellanic Cloud (LMC) has a unique cluster formation history in that nearly all of its globular clusters were formed either ∼13 Gyr ago or less than ∼3 Gyr ago. It is not clear what physical mechanism is responsible for the most recent cluster formation episode and thus the mysterious age gap between the LMC clusters. We first present results of gasdynamical N-body simulations of the evolution of the LMC in the context of its Galactic orbit and interactions with the Small Magellanic Cloud (SMC), paying special attention to the effect of tidal forces. We find that the first close encounter between the LMC and the SMC about 4 Gyr ago was the beginning of a period of strong tidal interaction that likely induced dramatic gas cloud collisions, leading to an enhancement of the formation of globular clusters that has been sustained by strong tidal interactions to the present day. The tidal interaction results in the formation of a barred, elliptical thick disk in the LMC. The model also predicts the presence of a large diffuse stellar stream circling the Galaxy, which originated from the LMC.
AB - The Large Magellanic Cloud (LMC) has a unique cluster formation history in that nearly all of its globular clusters were formed either ∼13 Gyr ago or less than ∼3 Gyr ago. It is not clear what physical mechanism is responsible for the most recent cluster formation episode and thus the mysterious age gap between the LMC clusters. We first present results of gasdynamical N-body simulations of the evolution of the LMC in the context of its Galactic orbit and interactions with the Small Magellanic Cloud (SMC), paying special attention to the effect of tidal forces. We find that the first close encounter between the LMC and the SMC about 4 Gyr ago was the beginning of a period of strong tidal interaction that likely induced dramatic gas cloud collisions, leading to an enhancement of the formation of globular clusters that has been sustained by strong tidal interactions to the present day. The tidal interaction results in the formation of a barred, elliptical thick disk in the LMC. The model also predicts the presence of a large diffuse stellar stream circling the Galaxy, which originated from the LMC.
KW - Galaxies: interactions
KW - Galaxies: star clusters
KW - Galaxies: stellar content
KW - Magellanic Clouds
UR - http://www.scopus.com/inward/record.url?scp=4043102682&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4043102682&partnerID=8YFLogxK
U2 - 10.1086/423372
DO - 10.1086/423372
M3 - Article
AN - SCOPUS:4043102682
VL - 610
SP - L93-L96
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 II
ER -