Hypercritical Accretion for Black Hole High Spin in Cygnus X-1. (arXiv:2201.05611v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Qin_Y/0/1/0/all/0/1">Ying Qin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shu_X/0/1/0/all/0/1">Xinwen Shu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yi_S/0/1/0/all/0/1">Shuangxi Yi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_Y/0/1/0/all/0/1">Yuan-Zhu Wang</a>

Recent observations of AdLIGO and Virgo have shown that the spin measurements
in binary black hole (BH) systems are typically small, which is consistent with
the predictions by the classical isolated binary evolution channel. In this
standard formation channel, the progenitor of the first-born BH is assumed to
have efficient angular momentum transport. The BH spins in high-mass X-ray
binaries (HMXBs), however, have been found consistently to be extremely high.
In order to explain the high BH spins, the inefficient angular momentum
transport inside the BH progenitor is required. This requirement, however, is
incompatible with the current understanding of conventional efficient angular
momentum transport mechanism. We find that this tension can be highly
alleviated as long as the hypercritical accretion is allowed. We show that, for
a case study of Cygnus X-1, the hypercritical accretion cannot only be a good
solution for the inconsistent assumption upon the angular momentum transport
within massive stars, but match its other properties reported recently.

Recent observations of AdLIGO and Virgo have shown that the spin measurements
in binary black hole (BH) systems are typically small, which is consistent with
the predictions by the classical isolated binary evolution channel. In this
standard formation channel, the progenitor of the first-born BH is assumed to
have efficient angular momentum transport. The BH spins in high-mass X-ray
binaries (HMXBs), however, have been found consistently to be extremely high.
In order to explain the high BH spins, the inefficient angular momentum
transport inside the BH progenitor is required. This requirement, however, is
incompatible with the current understanding of conventional efficient angular
momentum transport mechanism. We find that this tension can be highly
alleviated as long as the hypercritical accretion is allowed. We show that, for
a case study of Cygnus X-1, the hypercritical accretion cannot only be a good
solution for the inconsistent assumption upon the angular momentum transport
within massive stars, but match its other properties reported recently.

http://arxiv.org/icons/sfx.gif