The Eccentricity Distribution of Wide Binaries

Autor:	Benisty, David, Evans, N. Wyn, Davis, Anne-Christine
Rok vydání:	2022
Předmět:	Astrophysics - Solar and Stellar Astrophysics Astrophysics - Astrophysics of Galaxies Astrophysics - Instrumentation and Methods for Astrophysics General Relativity and Quantum Cosmology
Zdroj:	MNRS L Volume 518, Issue 1, January 2023, Pages L51-L56
Druh dokumentu:	Working Paper
DOI:	10.1093/mnrasl/slac134
Popis:	Future Gaia and Legacy Survey of Space and Time data releases, together with wide area spectroscopic surveys, will deliver large samples of resolved binary stars with phase space coordinates, albeit with low-cadence. Given an eccentricity law $f(\epsilon)$, we derive properties of (i) the velocity distribution $v/\sqrt{G M/r}$ normalised by the value for a circular orbit at the measured separation $r$; (ii) the astrometric acceleration distributions $a/\left(G M/r^2\right)$ again normalised to the circular orbit value. Our formulation yields analytic predictions for the full statistical distribution for some commonly used eccentricity laws, if the timescale of data-sampling is comparable to or exceeds the binary period. In particular, the velocity distribution for the linear eccentricity law is surprisingly simple. With Bayesian analysis, we suggest a method to infer the eccentricity distribution based on the measured velocity distribution. Comment: 6 figures; 6 pages
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2210.06429 Zobrazit plný text záznamu View this record from Arxiv