TY - JOUR

T1 - The thermodynamics of stellar multiplicity

T2 - an analytic model for the dynamical evolution of binary star populations in dense stellar environments due to single-binary interactions

AU - Leigh, N. W.C.

AU - Stone, N. C.

AU - Webb, J. J.

AU - Lyra, W.

N1 - Publisher Copyright:
© 2022 The Author(s).

PY - 2022/12/1

Y1 - 2022/12/1

N2 - We recently derived, using the density-of-states approximation, analytic distribution functions for the outcomes of direct single-binary scatterings. Using these outcome distribution functions, we present in this paper a self-consistent statistical mechanics-based analytic model obtained using the Fokker-Planck limit of the Boltzmann equation. Our model quantifies the dominant gravitational physics, combining both strong and weak single-binary interactions, which drives the time evolution of binary orbital parameter distributions in dense stellar environments. We focus in particular the distributions of binary orbital energies and eccentricities. We find a novel steady-state distribution of binary eccentricities, featuring strong depletions of both the highest and the lowest eccentricity binaries. In energy space, we compare the predictions of our analytic model to the results of numerical N-body simulations, and find that the agreement is good for the initial conditions considered here. This work is a first step towards the development of a fully self-consistent semi-analytic model for dynamically evolving binary star populations in dense stellar environments due to direct few-body interactions.

AB - We recently derived, using the density-of-states approximation, analytic distribution functions for the outcomes of direct single-binary scatterings. Using these outcome distribution functions, we present in this paper a self-consistent statistical mechanics-based analytic model obtained using the Fokker-Planck limit of the Boltzmann equation. Our model quantifies the dominant gravitational physics, combining both strong and weak single-binary interactions, which drives the time evolution of binary orbital parameter distributions in dense stellar environments. We focus in particular the distributions of binary orbital energies and eccentricities. We find a novel steady-state distribution of binary eccentricities, featuring strong depletions of both the highest and the lowest eccentricity binaries. In energy space, we compare the predictions of our analytic model to the results of numerical N-body simulations, and find that the agreement is good for the initial conditions considered here. This work is a first step towards the development of a fully self-consistent semi-analytic model for dynamically evolving binary star populations in dense stellar environments due to direct few-body interactions.

KW - binaries: general

KW - globular clusters: general

KW - scattering

UR - http://www.scopus.com/inward/record.url?scp=85145252845&partnerID=8YFLogxK

U2 - 10.1093/mnras/stac2907

DO - 10.1093/mnras/stac2907

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:85145252845

SN - 0035-8711

VL - 517

SP - 3838

EP - 3853

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 3

ER -