Details

Autor(en) / Beteiligte

• Grudzinska, M
• Belczynski, K
• Casares, J
• de Mink, S. E
• Ziolkowski, J
• Negueruela, I
• Ribó, M
• Ribas, I
• Paredes, J. M
• Herrero, A
• Benacquista, M

Titel

On the formation and evolution of the first Be star in a black hole binary MWC 656

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2015-09, Vol.452 (3), p.2773-2787

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which is very intriguing because this evolutionary stage is thought to be too fast to lead to significant accretion and spin up of the B star. We predict ∼10–100 of B-BH binaries to currently reside in the Galactic disc, among which around 1/3 contain a Be star, but there is only a small chance to observe a system with parameters resembling MWC 656. If MWC 656 is representative of intrinsic Galactic Be-BH binary population, it may indicate that standard evolutionary theory needs to be revised. This would pose another evolutionary problem in understanding black hole (BH) binaries, with BH X-ray novae formation issue being the prime example. Future evolution of MWC 656 with an ∼5 M⊙ BH and with an ∼13 M⊙ main-sequence companion on an ∼60 d orbit may lead to the formation of a coalescing BH–NS (neutron star) system. The estimated Advanced LIGO/Virgo detection rate of such systems is up to ∼0.2 yr−1. This empirical estimate is a lower limit as it is obtained with only one particular evolutionary scenario, the MWC 656 binary. This is only a third such estimate available (after Cyg X-1 and Cyg X-3), and it lends additional support to the existence of so far undetected BH–NS binaries.