Weighing in on black hole binaries with bpass: LB-1 does not contain a 70 M⊙ black hole. Issue 3 (23rd May 2020)

• Record Type: Journal Article
• Authors: Eldridge, J J; Stanway, E R; Breivik, K; Casey, A R; Steeghs, D T H; Stevance, H F
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 495:Issue 3(2020)
• Page Start: 2786
• Page End: 2795
• Publication Date: 2020-05-23
• Subjects: astrometry -- binaries: close -- stars: individual: LB-1 -- Galaxy: stellar content; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa1324
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The recent identification of a candidate very massive (70 M⊙ ) black hole (BH) is at odds with our current understanding of stellar winds and pair-instability supernovae. We investigate alternate explanations for this system by searching the bpass v2.2 stellar and population synthesis models for those that match the observed properties of the system. We find binary evolution models that match the LB-1 system, at the reported Gaia distance, with more moderate BH masses of 4–7 M⊙ . We also examine the suggestion that the binary motion may have led to an incorrect distance determination by Gaia . We find that the Gaia distance is accurate and that the binary system is consistent with the observation at this distance. Consequently, it is highly improbable that the BH in this system has the extreme mass originally suggested. Instead, it is more likely to be representative of the typical BH binary population expected in our Galaxy.