TY - JOUR
T1 - The fate of wide binaries in the solar neighborhood
T2 - Encounters with stars and molecular clouds
AU - Weinberg, Martin D.
AU - Shapiro, Stuart L.
AU - Wasserman, Ira
N1 - Funding Information:
We thankM artinD uncanA, my Liu, Piet Hut, Carl Sagan,a nd Scott Tremainefo r discussionsW. e also thankM ark Bailey for detailedc ommentosn the manuscript.T his work was supporteidn part by National ScienceF oundationG rant AST 81-16370t o Cornell University.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1986/1
Y1 - 1986/1
N2 - The time evolution of wide binaries by stochastic encounters with field stars and molecular clouds in the solar neigborhood is computed with a hybrid Monte Carlo scheme. Specifically, a Fokker-Planck analysis is used for distant encounters and the effects of close encounters are treated encounter by encounter. This approach has a considerable advantage in speed over direct integration methods, enabling the evolution to be computed for a wide range of initial semimajor axes, a0, and environmental parameters. We present the probability that a binary has achieved a new semimajor axis, P[a; a0, τ], for several values of a0 and for several characteristic times such as τ = 2.5 × 108, 3.0 × 109, and 4.5 × 109 years. We also present the probability of survival as a function of time for a0 between 0.01 and 1 pc. The former indicates how an initial distribution of binaries may be expected to evolve and the latter provides a semimajor axis cutoff which may be compared with observations. In order to use the observations together with the Monte Carlo results as a diagnostic probe, we investigate the sensitivity of these simulations to assumptions about the solar neighborhood. As an example, we consider the lifetime and stability of the proposed solar companion. Approximate analytic scaling of all key quantities with assumed environmental parameters is derived and compared with the simulations. The hybrid simulations reveal two physical effects not taken into account by the scaling relations.
AB - The time evolution of wide binaries by stochastic encounters with field stars and molecular clouds in the solar neigborhood is computed with a hybrid Monte Carlo scheme. Specifically, a Fokker-Planck analysis is used for distant encounters and the effects of close encounters are treated encounter by encounter. This approach has a considerable advantage in speed over direct integration methods, enabling the evolution to be computed for a wide range of initial semimajor axes, a0, and environmental parameters. We present the probability that a binary has achieved a new semimajor axis, P[a; a0, τ], for several values of a0 and for several characteristic times such as τ = 2.5 × 108, 3.0 × 109, and 4.5 × 109 years. We also present the probability of survival as a function of time for a0 between 0.01 and 1 pc. The former indicates how an initial distribution of binaries may be expected to evolve and the latter provides a semimajor axis cutoff which may be compared with observations. In order to use the observations together with the Monte Carlo results as a diagnostic probe, we investigate the sensitivity of these simulations to assumptions about the solar neighborhood. As an example, we consider the lifetime and stability of the proposed solar companion. Approximate analytic scaling of all key quantities with assumed environmental parameters is derived and compared with the simulations. The hybrid simulations reveal two physical effects not taken into account by the scaling relations.
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U2 - 10.1016/0019-1035(86)90061-8
DO - 10.1016/0019-1035(86)90061-8
M3 - Article
AN - SCOPUS:46149138660
SN - 0019-1035
VL - 65
SP - 27
EP - 36
JO - Icarus
JF - Icarus
IS - 1
ER -