Probing initial distributions of orbital eccentricity and disc misalignment via polar discs

¹ Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy
e-mail: simone.ceppi@unimi.it
² Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
³ School of Physics and Astronomy, Monash University, Clayton, VIC 3800, Australia
⁴ Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK

Received: 24 October 2023
Accepted: 15 December 2023

Abstract

In a population of multiple protostellar systems with discs, the sub-population of circumbinary discs whose orbital plane is highly misaligned with respect to the binary’s orbital plane constrains the initial distribution of orbital parameters of the whole population. We show that by measuring the polar disc fraction and the average orbital eccentricity in the polar discs, one can constrain the distributions of initial eccentricity and mutual inclination in multiple stellar systems at birth.