Direct Statistical Constraints on the Natal Kick velocity of a Black Hole in an X-ray Quiet Binary by Sharan Banagiri et al. on Wednesday 30 November

In recent years, a handful of ``dark" binaries have been discovered with a

non-luminous compact object. Astrometry and radial velocity measurements of the

bright companion allow us to measure the post-supernova orbital elements of

such a binary. In this paper, we develop a statistical formalism to use such

measurements to infer the pre-supernova orbital elements, and the natal kick

imparted by the supernova (SN). We apply this formalism to the recent discovery

of an X-ray quiet binary with a black hole, VFTS 243, in the Large Magellanic

Cloud. Assuming an isotropic, Maxwellian distribution on natal kicks and using

broad agnostic mass priors, we find that kick velocity can be constrained to

less than $V_k < 56$ km/s and the dispersion of the kick distribution to

$\sigma_k < 66 $ km/s at 90 \% confidence. Assuming that there was a natal

kick, we find that at least about $0.6 M_{\odot}$ was lost during the supernova

with 90 \% confidence. The pre-SN orbital separation is found to be robustly

constrained to be around $0.43$ AU.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16361v1