Over the past 8 years, Advanced LIGO and Advanced Virgo have detected about 90 gravitational-wave (GW) events, all of them produced by the coalescence of a compact binary system (CBC). In addition to CBCs, new types of GW signals are expected to be observed in the near future, as the sensitivity and observing time of GW detectors increase. Among them, we refer to long-duration transients as GW signals whose duration in the frequency band of the detectors ranges from few seconds to hours.

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We are now routinely detecting gravitational waves (GW) emitted by
merging black holes and neutron stars. Those are the afterlives of
massive stars that formed all across the Universe - at different times
and with different metallicities.
Birth metallicity plays an important role in the evolution of massive
stars.
Consequently, the population properties of mergers are sensitive to the
metallicity dependent cosmic star formation history (fSFR(Z,z)).

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