Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-12-05
Astronomy and Astrophysics
Astrophysics
10 pages including 9 figures, LaTeX (aa.cls). Accepted for publication in A&A main journal
Scientific paper
We present the tidal tail distributions of a sample of candidate binary clusters located in the bar of the Large Magellanic Cloud (LMC). One isolated cluster, SL 268, is presented in order to study the effect of the LMC tidal field. All the candidate binary clusters show tidal tails, confirming that the pairs are formed by physically linked objects. The stellar mass in the tails covers a large range, from $1.8\times 10^3$ to $3\times 10^4$\msun. We derive a total mass estimate for SL 268 and SL 356. At large radii, the projected density profiles of SL 268 and SL 356 fall off as $r^{-\gamma}$, with $\gamma= 2.27$ and $\gamma=3.44$, respectively. Out of 4 pairs or multiple systems, 2 are older than the theoretical survival time of binary clusters (going from a few $10^6$ yr to $10^8$ yr). A pair shows too large age difference between the components to be consistent with classical theoretical models of binary cluster formation (Fujimoto & Kumai 1997). We refer to this as the ``overmerging'' problem.A different scenario is proposed: the formation proceeds in large molecular complexes giving birth to groups of clusters over a few $10^7$ yr. In these groups the expected cluster encounter rate is larger, and tidal capture has higher probability. Cluster pairs are not born together through the splitting of the parent cloud, but formed later by tidal capture. For 3 pairs, we tentatively identify the star cluster group (SCG) memberships. The SCG formation, through the recent cluster starburst triggered by the LMC-SMC encounter, in contrast with the quiescent open cluster formation in the Milky Way can be an explanation to the paucity of binary clusters observed in our Galaxy.
Bergond Gilles
Leon Stephane
Vallenari Antonella
No associations
LandOfFree
Interacting star clusters in the LMC - Overmerging problem solved by cluster group formation 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 Interacting star clusters in the LMC - Overmerging problem solved by cluster group formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interacting star clusters in the LMC - Overmerging problem solved by cluster group formation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-457933