Item

Abstract

Gravitational waves emitted by asymmetric rotating neutron stars are the
primary targets of continuous gravitational-wave searches. Neutron stars in
binary systems are particularly interesting due to the potential for
non-axisymmetric deformations induced by a companion star. However, all-sky
searches for unknown neutron stars in binary systems are very computationally
expensive and this limits their sensitivity and/or breadth. In this paper we
present results of a search for signals with gravitational-wave frequencies
between $50$ and $150$~Hz, from systems with orbital periods between $100$ and
$1\,000$ days and projected semi-major axes between $40$ and
$200$~light-seconds. This parameter-space region has never been directly
searched before. We do not detect any signal, and our results exclude
gravitational-wave amplitudes above $1.25 \times 10^{-25}$ at $144.32$~Hz with
$95\%$ confidence. Our improved search pipeline is more sensitive than any
previous all-sky binary search by about $75\%$.