Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-02-10
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
45 pages, 13 figures, 2 tables; Accepted for publication in MNRAS
Scientific paper
We present the results of a numerical simulation of the history and future development of the Pleiades. This study builds on our previous one that established statistically the present-day structure of this system. Our simulation begins just after molecular cloud gas has been expelled by the embedded stars. We then follow, using an N body code, the stellar dynamical evolution of the cluster to the present and beyond. Our initial state is that which evolves, over the 125 Myr age of the cluster, to a configuration most closely matching the current one. We find that the original cluster, newly stripped of gas, already had a virial radius of 4 pc. This configuration was larger than most observed, embedded clusters. Over time, the cluster expanded further and the central surface density fell by about a factor of two. We attribute both effects to the liberation of energy from tightening binaries of short period. Indeed, the original binary fraction was close to unity. The ancient Pleiades also had significant mass segregation, which persists in the cluster today. In the future, the central density of the Pleiades will continue to fall. For the first few hundred Myr, the cluster as a whole will expand because of dynamical heating by binaries. The expansion process is aided by mass loss through stellar evolution, which weakens the system's gravitational binding. At later times, the Galactic tidal field begins to heavily deplete the cluster mass. It is believed that most open clusters are eventually destroyed by close passage of a giant molecular cloud. Barring that eventuality, the density falloff will continue for as long as 1 Gyr, by which time most of the cluster mass will have been tidally stripped away by the Galactic field.
Converse Joseph M.
Stahler Steven W.
No associations
LandOfFree
The Dynamical Evolution of the Pleiades 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 The Dynamical Evolution of the Pleiades, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Dynamical Evolution of the Pleiades will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-67737