Constraining accretion efficiency in massive binary stars with LIGOVirgo black holes
Abstract
The growing sample of LIGOVirgo black holes (BHs) opens new perspectives for the study of massive binary evolution. Here, we study the impact of mass accretion efficiency on the properties of binary BH (BBH) mergers, by means of population synthesis simulations. We model mass accretion efficiency with the parameter $f_{\rm MT}\in[0.05,1]$, which represents the fraction of mass lost from the donor which is effectively accreted by the companion. Lower values of $f_{\rm MT}$ result in lower BBH merger rate densities and produce mass spectra skewed towards lower BH masses. Our hierarchical Bayesian analysis, applied to BBH mergers in the first and second observing run of LIGOVirgo, yields almost zero support for values of $f_{\rm MT}\le{}0.3$. This result holds for all the values of the commonenvelope efficiency parameter we considered in this study ($\alpha_{\rm CE}=1,$ 5 and 10). The lower boundaries of the 95% credible intervals are equal to $f_{\rm MT}= 0.40,0.45$ and 0.48 for $\alpha_{\rm CE}= 1,$ 5 and 10, respectively. This confirms that future gravitationalwave data can be used to put constraints on several uncertain binary evolution processes.
 Publication:

arXiv eprints
 Pub Date:
 October 2020
 arXiv:
 arXiv:2010.11220
 Bibcode:
 2020arXiv201011220B
 Keywords:

 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 7 pages, 3 figures, 1 table, comments welcome