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Abstract

We report results of a search for continuous gravitational waves from a
region covering the globular cluster Terzan 5 and the galactic center.
Continuous gravitational waves are expected from fast-spinning, slightly
non-axisymmetric isolated neutron stars as well as more exotic objects. The
regions that we target are believed to be unusually abundant in neutron stars.
We use a new loosely coherent search method that allows to reach unprecedented
levels of sensitivity for this type of search. The search covers the frequency
band 475-1500 Hz and frequency time derivatives in the range of [-3e-8, +1e-9]
Hz/s, which is a parameter range not explored before with the depth reached by
this search.
As to be expected with only a few months of data from the same observing run,
it is very difficult to make a confident detection of a continuous signal over
such a large parameter space. A list of parameter space points that passed all
the thresholds of this search is provided. We follow-up the most significant
outlier on the newly released O2 data and cannot confirm it. We provide upper
limits on the gravitational wave strength of signals as a function of signal
frequency.