| Type |
Conference Paper |
| Names |
Thomas Finzell, A. Geller, N. Gosnell, R. Mathieu |
| Proceedings Title |
Bulletin of the American Astronomical Society |
| Conference Name |
American Astronomical Society, AAS Meeting #217, #144.17 |
| Volume |
43 |
| Date |
January 1, 2011 |
| URL |
http://adsabs.harvard.edu/abs/2011AAS...21714417F |
| Library Catalog |
NASA ADS |
| Abstract |
We model the origin of the binary star system, NGC 6819-3002-a highly
improbable star system that is likely the remnant of a dynamical
encounter. The horizontal-branch primary star would have had a large
enough radius while in it's giant phase to engulf the orbit of the
secondary star, making it very unlikely that these two stars were born
together. In order to explore the likelihood that the binary was created
via a dynamical exchange interaction we use a scattering experiment
algorithm to simulate encounters between a single star and binary
system. We use this to investigate the possible initial parameters that
could produce the currently observed properties of the system. We
incorporate the scattering experiments within a genetic algorithm, which
searches over the large parameter space and iteratively selects initial
parameters that yield the observed binary. The genetic algorithm gives
us the ability to confine the potential parameter space into one of a
computationally manageable size. We then perform a more systematic
search of the identified region of parameter space in order
to determine the multi-dimensional probability distribution of
parameters that can produce
NGC 6819-3002. We then correlate that probability distribution with the
distribution of binary and stellar parameters of NGC 6819 in order to
determine the likelihood that such a dynamical interaction could have
occurred. The result of this process shows that NGC 6819-3002 may indeed
have originated through a dynamical exchange interaction. Applying this
technique to additional stars and star systems in other clusters will
allow us to constrain the impact of dynamical encounters on the
formation of anomalous objects like NGC 6819-3002.
We gratefully acknowledge funding from the National Science Foundation
under grant AST-0908082. |