Abstract
We compile a sample of 341 binary and multiple star systems with the aim of
searching for and characterising Kuiper belt-like debris discs. The sample is
assembled by combining several smaller samples studied in previously published
work with targets from two unpublished Herschel surveys. We find that 38
systems show excess emission at 70 or 100 $\mu$m suggestive of a debris disc.
While nine of the discs appear to be unstable to perturbations from their host
binary based on a simple analysis of their inferred radii, we argue that the
evidence for genuine instability is not strong, primarily because of
uncertainty in the true disc radii, uncertainty in the boundaries of the
unstable regions, and orbital projection effects. The binary separation
distributions of the disc-bearing and disc-free systems are different at a
confidence level of $99.4\%$, indicating that binary separation strongly
influences the presence of detectable levels of debris. No discs are detected
for separations between $\sim$25 and 135 au; this is likely a result of
binaries whose separations are comparable with typical disc radii clearing out
their primordial circumstellar or circumbinary material via dynamical
perturbations. The disc detection rate is $19^+5_-3\%$ for binaries wider
than 135 au, similar to published results for single stars. Only
$8^+2_-1\%$ of systems with separations below 25 au host a detectable disc,
which may suggest that planetesimal formation is inhibited in binaries closer
than a few tens of au, similar to the conclusions of studies of known
planet-hosting binaries.
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