Speaker
Description
Subsolar-mass exotic compact objects (ECOs) are a possible clue to new physics beyond conventional astrophysics. When such an object orbits a stellar-mass black hole or neutron star, the resulting binary is a mini extreme mass-ratio inspiral (mini-EMRI) system. Gravitational waves emitted by mini-EMRI systems can last from hours to years in LIGO's frequency band, with characteristics closely resembling those of continuous gravitational waves. Such sources can therefore be searched for with ground-based detectors using continuous-wave detection methods, potentially enabling the detection of subsolar-mass ECOs. We perform parameter estimation for mini-EMRI systems using the Fisher information matrix to study how precisely ground-based detectors can measure the mass of subsolar-mass ECOs. For primary masses between $5$ and $50\, M\odot$ and secondary masses between $10^{-5}$ and $10^{-3}\, M_\odot$, we obtain the fractional errors of the secondary mass for different mass combinations. We further examine how the fractional error depends on the evolution time prior to the end of the inspiral and on the source distance for a fixed mass combination. Finally, we find that at a distance of $1\,\mathrm{Mpc}$, as long as the signal can be detected, the secondary mass of a mini-EMRI system can be constrained to the subsolar-mass range.