Interferometric detections of sdO companions orbiting three classical Be stars

Bibliographic Details
Title: Interferometric detections of sdO companions orbiting three classical Be stars
Authors: Klement, R., Schaefer, G. H., Gies, D. R., Wang, L., Baade, D., Rivinius, Th., Gallenne, A., Carciofi, A. C., Monnier, J. D., Mérand, A., Anugu, N., Kraus, S., Davies, C. L., Lanthermann, C., Gardner, T., Wysocki, P., Ennis, J., Labdon, A., Setterholm, B. R., Bouquin, J. Le
Publication Year: 2021
Collection: Astrophysics
Subject Terms: Astrophysics - Solar and Stellar Astrophysics
More Details: Classical Be stars are possible products of close binary evolution, in which the mass donor becomes a hot, stripped O or B-type subdwarf (sdO/sdB), and the mass gainer spins up and grows a disk to become a Be star. While several Be+sdO binaries have been identified, dynamical masses and other fundamental parameters are available only for a single Be+sdO system, limiting the confrontation with binary evolution models. In this work, we present direct interferometric detections of the sdO companions of three Be stars 28 Cyg, V2119 Cyg, and 60 Cyg, all of which were previously found in UV spectra. For two of the three Be+sdO systems, we present first orbits and preliminary dynamical masses of the components, revealing that one of them could be the first identified progenitor of a Be/X-ray binary with a neutron star companion. These results provide new sets of fundamental parameters that are crucially needed to establish the evolutionary status and origin of Be stars.
Comment: accepted to ApJ
Document Type: Working Paper
DOI: 10.3847/1538-4357/ac4266
Access URL: http://arxiv.org/abs/2112.05073
Accession Number: edsarx.2112.05073
Database: arXiv
More Details
DOI:10.3847/1538-4357/ac4266