SciPost Astro. 2, 002 (2022) ·
published 1 April 2022
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· pdf
A planet hardly ever survives the supernova of the host star in a bound
orbit, because mass loss in the supernova and the natal kick imparted to the
newly formed compact object cause the planet to be ejected. A planet in orbit
around a binary has a considerably higher probability to survive the supernova
explosion of one of the inner binary stars. In those cases, the planet most
likely remains bound to the companion of the exploding star, whereas the
compact object is ejected. We estimate this to happen to $\sim 1/33$ the
circum-binary planetary systems. These planetary orbits tend to be highly
eccentric ($e \ {\raise-.5ex\hbox{$\buildrel>\over\sim$}}\ 0.9$), and $\sim 20$\,\% of these planets have retrograde
orbits compared to their former binary. The probability that the planet as well
as the binary (now with a compact object) remains bound is about ten times
smaller ($\sim 3\cdot 10^{-3}$). We then expect the Milky way Galaxy to host
$\ {\raise-.5ex\hbox{$\buildrel<\over\sim$}}\ 10$ x-ray binaries that are still orbited by a planet, and $\ {\raise-.5ex\hbox{$\buildrel<\over\sim$}}\ 150$
planets that survived in orbit around the compact object's companion. These
numbers should be convolved with the fraction of massive binaries that is
orbited by a planet.
SciPost Astro. 1, 001 (2020) ·
published 14 May 2020
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We present the smoothed-particle hydrodynamics simulation code, Bonsai-SPH,
which is a continuation of our previously developed gravity-only hierarchical
$N$-body code (called Bonsai). The code is optimized for Graphics Processing
Unit (GPU) accelerators which enables researchers to take advantage of these
powerful computational resources. Bonsa-SPH produces simulation results
comparable with state-of-the-art, CPU based, codes, but using an order of
magnitude less computation time. The code is freely available online and the
details are described in this work.
Prof. Portegies Zwart: "It is a pleasure to respond to..."
in Submissions | report on Lucky planets: how circum-binary planets survive the supernova in one of the inner-binary components